The Watson

""You are beautifully and perfectly balanced. In you sanity is personified. Do you realize what that means to me? When the criminal sets out to do a crime, his first effort is to deceive. Whom does he seek to deceive? The image in his mind is that of the normal man. There is probably no such thing actually - it is a mathematical abstraction. But you come as near to realizing it as is possible...how does this profit me? Simply in this way. As in a mirror I see reflected in your mind exactly what the criminal wishes me to believe. That is terrifically helpful and suggestive.""

- Hercule Poirot, to his Watson and Life Partner Captain Hastings, "Lord Edgware Dies"

The Watson is the character whose job it is to ask the same questions the audience must be asking and let other characters explain what's going on. Distinct from Mr. Exposition in that The Watson is The Storyteller archetype, and often allows another character to become Mr. Exposition within the story's context. May also be The Ishmael, with the entire story viewed from his eyes.

Generally, female variants of The Watson will have a bit more character development and a larger role within the story (but not too much larger). She will be inevitably attractive, serving a dual role -- giving the children someone to like and the adults someone to tune in for.

Children have it easier. Constantly Curious is a popular device, and may even force Mr. Exposition into that role.

Playing The Watson is also referred to as cabbaging, since this role could be played by a head of cabbage.

Science fiction fans may know this character as The Sarah Jane, after (arguably) the most popular of the many companions who had things explained to them on Doctor Who. In fact, actress Louise Jameson, who played another of the Doctor's companions, explained her decision to leave after a relatively short tenure as being motivated by the fact that, "There are only so many ways you can say 'What is it, Doctor?'"

On occasions, you get The Watson being cleverer than Mr. Exposition, which results in some problems, but occasionally works.

Often in fantasy settings, The Watson is the character with more "real world" sensibilities (sometimes because he's been transplanted from the real world: John Crichton (Farscape) often got to act as The Watson in early episodes, for example), prompting Mr. Exposition to explain the "rules" of the fantasy world.

In parody, it is becoming increasingly common for The Watson to be a character who isn't genre blind to the sillier tropes, often making Mr. Exposition look like something of a buffoon (as in Austin Powers: International Man of Mystery, where Scott Evil asks why his father doesn't just shoot Austin, instead preferring to put him in an easily escapable Death Trap). See Genre Savvy.

Aside from serving as an Audience Surrogate, the Watson can also play an important but often overlooked role in the story itself. As many of the examples show, the Watson's comments and actions often help the detective in figuring out the mystery. While the Watson may not be able to solve the cases himself, he often gives the detective the final crucial insights that point him in the right direction.

See also The Snark Knight, who makes similar observations but is much less inclined to assist afterwards. Not to be confused with The Ishmael - if you were looking for a trope where the viewpoint character is intentionally distanced from the protagonist, click there.

...Has nothing to do with the Jeopardy!-winning IBM supercomputer of the same name, awesome as it is.

Anime and Manga

 * We rarely ever get a first-person perspective on Akagi's thoughts - as the point of view is mainly given to Yasuoka (oddly enough a detective), who observes and attempts to decrypt Akagi's genius from the sidelines.
 * In Death Note, Ryuk, a Shinigami, often acts as The Watson to Light's plans. That is, when he's not just standing behind Light silently chuckling. Or standing on his head.
 * Touta Matsuda in the same series is used as The Watson for the police side of events, mainly due to his being a male version of The Ditz.
 * Amnesia!Light and Watari are also this to L, being just different ages in Watson.
 * Manta Oyamada in Shaman King acts as The Watson to Yoh Asakura, being the narrator but not The Hero.
 * Hiyono in Spiral tends to get dropped into this role, and if she isn't, Kousuke is. Hiyo-Hiyo is reasonably clever, and Kou-chan even more so, but that doesn't say much when the entire main cast is made up of child prodigies.
 * Rick Wheeler/Ryu Suzaku in F-Zero: Falcon Densetsu. (You know this show as the one that Ascended "FALCON PUUUUUUUNCH!!!")
 * Normally inteligent Chachamaru in Mahou Sensei Negima was always and entirely uninformed of any fighting style during the Mahora Tournament. Giving us Explainer Goutokuji for this portion of the series. Normally Asuna, Nodoka, Konoka, and Chisame serve this purpose. Yue bounces between this and Mr. Exposition depending on where in the series you are. When it comes to fighting Negi takes this role, giving the big Exposition talk to Kaede (Ninja), Ku Fei (Kung Fu Master), Kotaro (Dog Demon Brawler Ninja), or Evangaline (Really Old Vampire).
 * Despite being from the same magical world as everyone else, Gourry from Slayers was enough of an idiot to have to ask questions about what the other characters would consider basic, everyday facts, giving them a reason to explain the rules and mythology of their world.
 * Though it should be noted that the other characters consist of a professional and incredibly well-studied sorceress, a princess who is herself a sorceress (albeit of white magic), an ancient demon, and a sorcerer who also happens to have originally been on extremely good terms (thanks to the whole blood relation thing) with someone considered one of the wisest men in the whole world. What's "basic, everyday facts" to them may not be the same to someone who hasn't spent years studying occultic lore and pouring over magic grimoires.
 * This is averted in the original series of novels the anime is based off of; protagonist Lina herself is the narrator and Gourry, while still uninformed, is no where near as idiotic.
 * The titular character of Naruto frequently had to play this role early on, being a shining example of Book Dumb. It's almost mystifying that ten episodes in you'll probably know more about the geography, Functional Magic, and infrastructure of the story's world than he did when he graduated.
 * Akari from Aria has some of this. Alicia could have picked a local girl for an apprentice, but instead she chose someone who needs a lot of explanations about the planet she moved to--which then of course raises the question why Akari didn't read a travel guide beforehand.
 * Detective Conan plays this straight, inverts and subverts this till kingdom come. Depending on the case, and which characters are present at the time, any number of characters will play Watson to Conan's Holmes... Ai, the Detective Boys, Ran, the cops, Eri, Jodie, etc. Conan pretends to be The Watson to Kogoro, even acting out this part after putting Kogoro to sleep. Not to mention the times Kogoro inadvertantly plays Watson to Conan.
 * Kuwabara from Yu Yu Hakusho is the guy who asks the questions so that Hiei and Kurama can avoid having to use As You Know when being Mr. Exposition. When he got Put on a Bus in the final season to pursue a higher education, the anime attempted to spread this role out amongst the other characters; it didn't work out too well.
 * Elsee in The World God Only Knows is often asking why Keima is doing what he is doing. The explanations, however, are not always comprehensible (and are often funny because of that).
 * Roji tends to play this role in Muhyo and Roji's Bureau of Supernatural Investigation, often about the workings of magical law or Muhyo's past. Other times, the clients ask the questions.
 * Kotori Mizuki of Yu-Gi-Oh Ze Xal is this in regards to the card game.
 * Nonoha in Phi Brain Kami no Puzzle serves this role as the rest of the main cast are puzzle-solving geniuses, so she gets to stand in for the audience and ask any questions needed about the various puzzles they are confronted with.
 * In Bakuman｡, Takagi served this role in the first volume, asking Mashiro about how the manga industry worked (Mashiro happened to have a mangaka uncle). Later on, Miyoshi filled this role as the characters became more familiar with the industry.
 * Darker than Black played with this, as in the very first episode a scientist explained on the run basics about what's going on to a lad who just happened to be around when she didn't know where to go from her Ransacked Room and was nice enough to help. Which neatly  demonstrated   the style of this 'verse.

Comic Books

 * Robin, and to a lesser extent Alfred tend to play this role to Batman. This is even part of the reason Robin was created.
 * Rick Jones of various Marvel Comics sidekick roles. Though sometimes his leading Hero would be the Sherlock, sometimes various experts would be the Sherlock, but most commonly after getting captured, Mr. Exposition would be the one who was supposed to be interrogating him.
 * Crispus Allen plays the Watson in the early issues of Gotham Central, and occasionally later on. As a transferred officer from Metropolis, Allen did not have extensive experience with the "freaks" (supervillains) of Gotham City, so other characters would explain their means and methods to him, simultaneously infoming the audience as well. This particular facet of his character was dropped after a few issues, when he already had his own personal experiences with the rogues of the city, but he would later serve as the Watson on more complex issues when characters needed to highlight personal and societal points about Gotham City itself, such as the reason why Batman is important to Gotham for more than just the crimes he stops.
 * Once she learned his secret identity, Peter Parker's wife, Mary Jane Watson Parker Watson occasionally served this role for him, asking him things about the superhero business. One of the best examples of her being used in this fashion was in the story Hobgoblin Lives! where Peter had to fill her in on the background for the story (since the stories it happened in were written years ago) and she asked the simple question that led to a plot breakthrough.
 * Unintentional Stealth Pun there.
 * In Doctor Strange: The Oath, Night Nurse is along for the adventure at her own insistence (Strange has been wounded and she is a physician). Strange's assistant Wong is also present as a sort of minor Holmes/experienced Watson, answering some questions and asking others.

Fan Works

 * In Luminosity, Bella sets up some scientific experiments to prove that the Cullens are really vampires...and once she's convinced she's just fascinated with the fact that they exist and generally tries to learn more. About everything.
 * Luso, and to a lesser extent, Hurdy, get things they don't know about explained to them by other characters in The Tainted Grimoire.

Film
"Forget it, Donnie, you're out of your element!"
 * Jack Ryan in The Hunt for Red October plays The Watson for all the submarine action, letting the boat captains play Mr. Exposition. Similarly, Seaman Beaumont plays The Watson for sonar terms, letting Sonar Technician Jones explain everything.
 * In the DVD commentary for Ghostbusters, Ivan Reitman says the character of Winston Zeddemore was intended to serve this purpose.
 * Marty McFly fills this role from time to time in Back to The Future so Doc can explain some of the time travel mechanics.
 * Massively subverted by Donnie in The Big Lebowski, who is utterly Locked Out of the Loop.


 * In the movie Fantastic Voyage, and in the Isaac Asimov novelization, The Watson is secret agent and former combat swimmer Charles Grant. Asimov's version makes him a bit less of a dunce; on occasion, Grant can actually figure something out from his general knowledge of human anatomy, instead of needing the knowledge spoonfed to him.
 * Terminator: Salvation: Marcus
 * The Terminator: Sarah Connor
 * Terminator II: John Connor
 * Terminator 3: Kate Brewster
 * Averted by Watson from the 2010 Sherlock Holmes film. He is less Watson-y than Watson's from almost any other adaptation and shows intuitive and deductive skills which he picked up from his time working with Holmes. This is truer to the original Watson: a skilled and intelligent medical practitioner, decorated war veteran, and good man in a brawl.
 * John Myers in the first Hellboy movie, especially since no such character exists in the comics.
 * James Edwards/Jay in Men in Black.
 * Dr. Karen Jenson in the first Blade film. She's left out of the remaining series because there's no need for her anymore.
 * Vittoria Vetra in the film adaptation of Angels & Demons. Thanks to editing for time constraints, it's pretty much all she's there for.
 * Ariadne in Inception. She asks the questions about inception and extraction that the viewer would be asking. Saito is also this to some extent, at least in the beginning of the film.
 * Apollo 13: Jim Lovell's youngest son, Jeffrey, asks his father about his upcoming mission, i.e. how long it'll take to get to the moon and the function of the lunar module. Jim also explains what went wrong in the Apollo 1 disaster, briefly depicted in the beginning of the movie.

Literature

 * The trope namer is Dr. John Watson, the narrator from the Sherlock Holmes stories by Arthur Conan Doyle, who often asks the title character to explain his baffling logical leaps. Holmes then explains the logic used in solving the case, allowing the author to describe the finer points of the story without disrupting the narrative flow. Unlike the character found in some lesser adaptations, Watson is not a chubby dullard, but a very intelligent and bold man who occasionally contributes his own observations to cases, though he is not always completely correct. Holmes often makes use of Watson's medical knowledge and fresh perspective to keep his deductions sharp. In A Study In Scarlet, a puzzled Watson rattles off all the unanswered questions about the case, and Holmes commends him for pointing out the main difficulties. It's implied that Holmes is glad to have someone who he can fruitfully discuss the case with, which is more than can be said for Inspectors Lestrade and Gregson. Holmes even acknowledges Watson's importance in providing him with critical insights, saying, "...you are not yourself luminous, but as a conductor of light, you are unparalleled!"
 * Captain Hastings in several of Agatha Christie's Hercule Poirot stories, on the other hand, was most definitely The Watson - in fact, he resembled the flanderized Watson more than the original Watson did. He readily Lampshaded this fact too, calling himself "the humble Watson" in jest.
 * Dr. Sheppard fulfills this role in The Murder of Roger Ackroyd when Poirot is on a Busman's Holiday.
 * Most stories about a Utopia, particularly those written before the mid-twentieth century, tend to feature a lead character who is a Watson combined with a Naive Newcomer. The plot generally consisted of the Watson being led around the utopia asking questions about how it works. The Exposition Fairy who lived in the utopia would then explain how the utopia worked in exhaustive detail. Really poorly thought out utopian novels did not combine this trope with the Naive Newcomer and hence had the Exposition Fairy tell The Watson things they already knew for no apparent reason. Generally declined in usage after modern exposition techniques, (ie "Show, Don't Tell") were developed. Examples include Julian West from Looking Backwardby Edward Bellamy, Guest from News from Nowhere by William Morris, and the Botanist from A Modern Utopia by H. G. Wells. An example of a Watson who isn't combined with the Naive Newcomer is Alice from Ralph 124C 41+ by Hugo Gernsback.
 * Slightly subverted in The Twenty-One Balloons, where the Naive Newcomer only needed the weirdest elements of the utopia explained to him.
 * In the Aubrey-Maturin series, Stephen Maturin acts as a Watson in all matters nautical, conveniently (for the reader) refusing to learn to tell one sail from another however long he lives on a ship.
 * The narrator of Das Boot acts as both Watson and Mr. Exposition. He's on board as a journalist, thus it's his job to be inquisitive about everything, and pass on his knowledge. He has naval experience on surface ships but this is his first voyage on a submarine. The crew and officers sometimes pause to explain what they're doing to him but he often has to figure it out by observation.
 * In Umberto Eco's The Name of the Rose, Adso (the narrator) is the assistant of a Medieval detective named William of Baskerville, and inquires into the latter's deduction methods as the reader would. Unsurprisingly, both characters were inspired by Watson and Sherlock Holmes.
 * In The Thrawn Trilogy Captain Pellaeon serves as the villainous (somewhat) Watson to Grand Admiral Thrawn. He's also the best possible versions of Commander Contrarian and The Ishmael and, arguably, a protege.
 * Definitely a protege. In the later duology, he may not reach Thrawn-levels of skill, but his tactical sense and intuition have clearly been honed.
 * Interestingly enough, official artwork shows that he actually looks kind of like Watson-- or at least the Watson played by Edward Hardwicke. Which rather fits as easy to imagine Jeremy Brett with blue skin and glowing red eyes as Thrawn.
 * In the Honor Harrington series, Haven's Committee for Public Safety stations a Political Officer on each ship to watch over (a.k.a. second guess) naval officers. They play a darker version of this trope because captains often have to explain and justify their decisions to people with no military training while avoiding any appearance of disloyalty to a regime that executes captains to fail to carry out their orders and their whole families.
 * Eragon is always asking questions, to the point where a description of him one character gives to another includes "always asking questions".
 * Ron in Harry Potter was constantly making suggestions, forcing Hermione to sigh and explain that, if only he'd read Hogwarts: A History, he'd understand why it's impossible to... Rowling said she would never have Harry or Ron read Hogwarts: A History because it was too useful an expository device.
 * Harry is just as much of a Watson as Ron, albeit one who serves a different purpose. Having grown up with Muggles, there's a lot he doesn't know that people who grew up in the wizarding world would take for granted (Quidditch? What's that, some kind of illness?). Ironically, it's often Ron who gets to be Mr. Exposition in those situations, since unlike Hermione, he grew up in the wizarding world, and is therefore the only one of the main trio to have that sort of knowledge.
 * While Harry plays the Watson a good deal of the time, a few times he's considerably ahead of the others, and not just by blind luck either. At least two times in the final novel, he proves to be far ahead of the other two members of the Trio in figuring out what's going on.
 * And EVERYBODY is this trope for Albus Dumbledore. There's a "Dumbledore Explains It All" scene at the end of every book, except the sixth when it's not at the end. There's even one of those scenes in the last book, even though Dumbledore's dead at the time.
 * Tom Swift generally has one of these on hand. In the "Tom Swift, Jr." series of books published in the 1950s, it was Bud Barclay. The Recycled in Space! series which followed in the early 1980s had Benjamin Franklin Walking Eagle. One Continuity Reboot later, The Watson was Rick "test to destruction!" Cantwell.
 * Archie Goodwin, Watson to Nero Wolfe's Holmes. Subverted slightly in that Archie is a capable detective in his own right, and would frequently figure out the murderer just as Wolfe does. Since he writes his "reports" for an audience, however, he usually doesn't let the reader in on it until Wolfe explains the mystery.
 * Like Watson, Archie frequently gets flanderized into a dull-witted womanizer in adaptations, with only his outstanding memory being kept.
 * In Robert E Howard's Conan the Barbarian story "Beyond the Black River," Balthus. Conan repeatedly explains his acts, both how and why, to him.
 * Both played straight and parodied/heavily lampshaded in AA Milne's The Red House Mystery, where the Amateur Sleuth Anthony outright asks his friend Bill to play Watson to his Holmes, specifically defining Bill's role as asking stupid questions and needing even the most obvious things explained to him. And indeed, this is what Bill does -- but half the time he's asking the questions because Anthony tells him to rather than because he's actually incapable of figuring out the answers, and sometimes he gets fed up with his friend's Sherlockian pretensions.
 * In the Simon Ark short stories, Simon's publisher (who is also the narrator of the stories) fills this role.
 * A variety of characters fill this role for Horne Fisher, the central character of GK Chesterton's The Man Who Knew Too Much.
 * The naive but pure-hearted Ten Ox plays this role to the cunning and knowledgeable sage Li Kao in Bridge of Birds. There's actually an early draft of the book that reveals the author had originally intended for Li Kao to be the narrator and Ten Ox to be only a peripheral character. Comparing this draft with the final product shows just how much the promotion of Ten Ox to this character role (and the addition of many plot elements) improved the book; for one thing, Li Kao's narration of his life story isn't quite as effective when he tells it in a drunken ramble to a skull in a pool as when he tells it to Ten Ox to assure him that he's not going to give up in his quest to heal the ill children of Ten Ox's village.
 * Detective Sergeant Mary Mary in the Nursery Crime novels is a pastiche of the trope in British detective drama. Coming from outside the area she's somewhat Genre Blind to the mixture of detective and nursery rhyme tropes that dominate Reading, so DI Spratt has to clue her in on this as well as explaining the case to her.
 * Peter plays this role in Peter and the Starcatchers. There's a whole chapter where Molly has to give him a long Character Filibuster to explain the history of the Starcatchers.
 * Bertie Wooster sometimes has to grill Jeeves at great length to figure out what, exactly, is going on. Bonus Points because PG Wodehouse was a big Sherlock Holmes fan and occasionally threw in a reference to the characters.
 * Sister Fidelma, Irish nun and law official in the books by Peter Tremayne, has the Saxon monk Brother Eadulf, later her husband (which was allowed in the Celtic Church). In some of the stories where Eadulf doesn't appear, Abbot Laisran serves the role, creating an interesting dynamic since he's her superior in the church, but not in the courts.

Live Action TV
"Be my Doctor Who girl, follow me a lot Ask me heaps of questions So I can explain the plot"
 * In Magnum, P.I., Magnum had an annoying friend named Rick. His function in the series was to serve as a sort of surrogate for the audience on the more outrageous story points. He was always protesting, "C'mon, Magnum..." as in, "C'mon, Magnum, there's no way those crooks would trust us with $7 million in gold coins. It's ludicrous." (And this is exactly what the audience was thinking at that point.) Magnum would then calmly explain to Rick just exactly why the crooks would, indeed, hand over $7 million in gold. Rick would be convinced, and in theory, the audience protests would have been addressed as well.
 * This trope was, it should be noted, once named The Rick.
 * The classic (1963-1989) series of Doctor Who featured countless characters that filled this role. The female companions evolved as the series went on, tending more towards the Action Girl; the last before the series was cancelled was Ace, a punk-rock teen who loved explosives and was willing to rush at a Dalek with a baseball bat if she saw one.
 * In one ep (just after he's 'lost' another one), the Doctor starts babbling to thin air, and then stops cause he realizes no one's listening.
 * Funnily enough, Sarah Jane herself gets her own Watsons in The Sarah Jane Adventures, in the form of Maria, Luke and Clyde (and later Rani). Though in this show it's the boys, and not Maria, who tend to get captured more often... though they are still savvy enough to get themselves out of it too.
 * In the newer episodes of Doctor Who, the Doctor himself is often The Watson, asking the natives of whatever time and place he's landed in what's going on and why they're doing what they're doing.
 * Parodied in the Mitch Benn song "Be My Doctor Who Girl":

"Kai: Books contain useful information... sometimes. And interesting stories... less often."
 * Gwen gets to fill this role on Torchwood.
 * On House MD the role of House's Watson is played by every single character. One memorable example had House saying his staff's diagnosis was wrong, because they weren't wearing the right shoes -- if the diagnosis was right, they'd all already be at a bowling alley.
 * Since Gregory House is heavily based on Sherlock Holmes, James Wilson is the main analogue to John Watson.
 * Every single character in every single episode of every single CSI can be the Watson. They find some rash or bacteria or wound or something on the corpse and then go on explaining what that means to the nearest character. Since that character is supposed to know that stuff as well, the whole dialogue turns into a circus of finishing sentences for the other character.
 * In Grissom's last episode, Hodges says he's Watson to Grissom's Holmes. Grissom reminds him that Watson was a genius in his own right.
 * The ditzy lab assistant in the "Science Fiction Sketch" on Monty Python's Flying Circus is very much a parody of the type; she exists simply to look pretty and have Graham Chapman's character explain the plot to her. He eventually becomes so frustrated with her stupidity that he knocks her out and explains the plot to himself instead.
 * Gus from Psych, one of the few characters in on the Masquerade, whose fair intelligence and relative lack of observancy make him just short of an Expy of Watson himself. The gap between his character and Expy status closes even further when you consider how often his pharmaceutical knowledge (an update of Watson's medical training) plays into solving cases.
 * In Red Dwarf, the Cat, Lister and Rimmer tend to share Watson duties, with Holly and Kryten acting as Mr. Exposition.
 * In Lost, it's Hurley. Officially; it was lampshaded by the executive producers in a podcast.
 * Clark Kent from Smallville fits this in that he's usually the one giving Chloe an opportunity to rattle off a short explanation of whatever clever trick she came up with. Bonus points if Clark wears his Big Dumb Alien™ expression to complete the cliche of Watson being a bit slow.
 * Applies to Maddy, Carla and now Joey in Jonathan Creek.
 * Whenever somebody explains something about how the Stargates function in Stargate Universe, they're explaining it to Eli. He's arguably more intelligent than most of the people explaining stuff to him, but by far the least experienced of the bunch.
 * Jack O'Neill of Stargate SG-1 was the same. While a Colonel Badass and good leader, he'll still have to ask the two geniuses or the alien about whatever bit of Applied Phlebotinum is about. Whether or not he was portrayed as generally unintelligent, or merely needing to leave blowing up suns to Samantha Carter, wavered.
 * The core cast of Lexx had a pretty clear division between Holmeses and Watsons. Kai was 2000 years old with thousands of strangers' lifetimes in his memory, 790 was a robot with knowledge of every sector in the universe (and wireless internet directly to his brain), and Stan and Xev were illiterate fugitives from a world where humans lived in boxes and were taught nothing more than needed to do their jobs. They not only needed explanations for Polarity Reversal and star lifting, but also for concepts like books.

"[THRUSH operative Randolph, having gotten Dr. Simon True's seawater-to-gold extraction formula away from U.N.C.L.E., is gloating before Solo and Kuryakin] Randolph: Imagine, tons of gold, tons! Pouring into our storage vats. [Kuryakin raises his hand] Yes? Illya Kuryakin: Won't this Midas-land master plan defeat its own object? With gold as plentiful as dust, won't it lose its value? Randolph: We will control its rate of release, don't you worry. Napoleon Solo: We won't."
 * Illya Kuryakin played The Watson at the climax of the third season The Man from U.N.C.L.E. episode "The Five Daughters Affair, Part II":

"John: How--Oh, never mind."
 * Wallace Fennel is the Watson to Veronica Mars, especially at the start of season 1, since he is new to Neptune.
 * Donna usually played this role in The West Wing, at least in the early years. Her job was to badger Josh with all the questions the audience was asking, "But Josh, why is policy x important?" "Josh, why should we loan Mexico millions?" In the later seasons she received Character Development and moved beyond this role, occasionally needing her own Watson.
 * Booth to Brennan in Bones, though it could argued that they really ping-pong the role between them depending whether they're dealing with the forensic or detective aspect of the investigation. But when you consider Booth's past as a soldier in the Middle East and the fact that Brennan is a doctor consulting to law enforcement you can clearly see their fictional lineage. The Squints are unquestionably the Baker Street Irregulars.
 * The police with whom the BAU team up in Criminal Minds often serve this purpose. Each episode has a scene where the team deliver a profile explaining the killer's psychology to the police, and thus also to the audience.
 * Occasionally subverted when the cops grab the wrong end of the stick and completely misunderstand the profile, or think about it and realize it applies to half the local population.
 * On The A-Team, Face was usually this to Hannibal when he explained that episode's plan, bringing up potential snags and problems that they could run into, but Murdock, B. A., and/or (in the early seasons) Amy or Tawnia could fill this role instead or simultaneously.
 * In Prison Break, Sucre was The Watson to Michael during the first season. Lampshaded by the actor, who commented on how his main role in the plot was to ask Michael "what are you doing?" or "what do we do next?" In later seasons, this role would fall to whoever happened to be with Michael at the time, such as Lincoln and Sara. Mahone also had his own Watson during season 2, but since Mahone was a baddie at the time, it didn't quite play out the same way.
 * Tori Vega in Victorious, as a New Transfer Student who is a talented musician but untrained, is this with her asking questions that the rest of the cast can then explain what certain theatrical or musical plot relevant terms mean in case the audience don't know.
 * Teresa Lisbon to Patrick Jane in The Mentalist.
 * In Eureka, Jack Carter is the Watson to most of the other characters in rapid succession so they can all have a go at explaining the current threat and science behind the solution.
 * Daphne played this sort of role in Frasier, asking the Cranes to explain what the hell they were talking about whenever they got involved in something pertaining to their younger years or family affairs (which was many, many episodes). This was so the Cranes would have a legitimate reason to tell a hasty expositionary story that they all already were clear on about their past so the audience knew what the problem they had this time was. Roz occasionally fulfilled this role too.
 * On the BBC modernisation of the Trope Namer, Sherlock, this role is filled by Doctor John Wat-[Beat] Ah. Right.


 * Every UK detective drama features a stolid Detective Sergeant or Constable who the Detective Inspector can explain things to.
 * Inspector Morse had Sergeant Lewis, then Inspector Lewis had Sergeant Hathaway.
 * DCI Jim Taggart had DS Michael Jardine and DS Jackie Reid, then DCI Jardine had DS Reid and DC Stuart Fraser. Currently DCI Matthew Burke, DI Reid and DI Robbie Ross have DS Mita Rahim.
 * DCI Tom Barnaby had Sergeant Troy, replaced first by Sergeant Scott and then by Sergeant Jones, who continues to serve as The Watson to Barnaby's Suspiciously Similar Substitute cousin, DCI John Barnaby.
 * DI Jack Frost has a rotating cast of sidekicks. The most prominent ones are DS Hazel Wallace and DS C Live Barnard.
 * Similar to the Frasier example above, Robin was this in the first two or three seasons of How I Met Your Mother, asking questions about situations or conversations that relied on backstory from Ted, Marshall, and Lily's long, closely-shared history together so that the characters (or Future Ted) had an excuse to explain it to the viewer. It's implied Barney has had most of these things explained to him before 2005. By season 3-4, Robin (and the audience) had already gotten a huge amount of pre-series backstory and isn't much of a Watson anymore, and so the writers started to rely more on in-show established continuity to form the basis of these kinds of stories, usually heralded by Future Ted remarking "Kids, remember how I told you about that time..."
 * Mike Rowe of the documentary series Dirty Jobs is a professional Watson, learning the ropes of his latest dirty job from his bemused temporary co-workers.
 * In fact, many presenter-led documentaries use this technique.
 * An interesting variation happens on Columbo where the Watson is played by the murderer of the week who tries to use this relationship with the eponymous detective to try and veer him off their scent. It never works. They always slip up somewhere, and Columbo picks up on the critical clue.

Tabletop Games

 * In the Magic: The Gathering novel Test of Metal, Doctor Jest often serves this purpose, giving Tezzeret someone to converse with and explain things to when the story demands it.

Theatre
"Le Bret: But these strange ways, Where will they lead you, at the end? Explain Your system—come!"
 * Little Sally from the musical Urinetown is a parody of this.
 * Mary Lennox in the musical version of The Secret Garden takes on this role temporarily when Mrs. Medlock introduces her to her new home, conveniently telling Mary all the backstory of the home and the family for the audience to hear.
 * Cyrano De Bergerac:
 * Le Bret. Half of his dialogue is asking Cyrano the same questions the audience must be asking (why in hell did you something so jerkass/ stupid/ selfdestructive) and let Cyrano explain what's going on. The other half of his dialogue is scolding Cyrano for being a jerkass.


 * Subverted by the Duenna. She asks Raguenau why he intented to kill himself. After his response, she changes the conversation.
 * What happens when two of the dullest Watsons ever are left to themselves and try to ask one another the questions? Waiting for Godot. (Pozzo tries to be one too, but they're too incoherent to explain anything.)

Toys

 * Pohatu is rapidly becoming this in a recent Bionicle serial, as he is trying to solve a murder mystery with the increasingly Holmsian Kopaka.

Video Games

 * The various Snakes of the Metal Gear Solid franchise seem to serve this role well, although the exact reason why is pretty obvious. The original idea behind the protagonist switch was that Snake would have someone to be The Watson for him instead of being The Watson himself, letting him come across as more astute and mature. (Hideo Kojima even cited inspiration from Sherlock Holmes and Doctor Who for the idea.)
 * And he happens to be the most (only?) reality-grounded character in Super Smash Bros. Brawl to boot, making for some hilarious codec calls where he tries to come to grips with the weirdness of the game.
 * In Final Fantasy X, the Player Character Tidus fakes amnesia so that he can play the Watson to the rest of the cast (he actually has a real reason for not knowing the the things he asks about, but it doesn't fly too well with the xenophobic people he hangs around with). Unfortunately in order to make sure that every player is keeping up with the plot, Tidus finds himself constantly bugging people for exposition, to the point where his friends aren't sure if he's actually amnesiac or just an idiot. Fortuantely for everyone, he gets better as the plot goes on.
 * It gets to the point where Lulu starts explaining things before he even asks, leading him to comment that she's gotten so used to him asking questions that he barely needs to ask anymore.
 * A quote from Lulu after one too many explanations : " Are you sure it's not your brain that's the problem?"
 * Word of God has this as Dom's role in Gears of War, to give the audience a voice without bringing players out of the experience as Marcus.
 * Leonard, the main character of White Knight Chronicles (as opposed to your avatar who represents you, but has little story relevance). The other characters start Lampshading it early on, with a random chatter once the game proper kicks off involving two characters remarking on how bizarre it is that Leonard knows nothing about Bigelows -- who form the backbone of communication in The Verse, with their flight and ability to transmit images and voice between a pair allowing them to act as the setting equivalent to e-mail.
 * Lion Ushiromiya plays this role to the detective Willard H. Wright in the seventh arc of Umineko no Naku Koro ni. After a while they even start to refer to each other as "Watson" and "Holmes".
 * In Mass Effect, Liara takes this role. Due to Shepard having an entire library of Prothean data downloaded into their mind via one of their Beacons, this leaves Liara, as a Prothean expert, to try to delve inside the sheer masses of information present in Shepard's mind and attempt to understand what their visions actually mean.

Web Comics

 * In the webcomic Erfworld, the character Parson acts as both The Watson inside the narrative and Mr. Exposition through a diary.
 * Order of the Stick has a procession of short-lived hobgoblin cleric assistants that can cast Transmute Redcloak to Mr. Exposition at will.
 * Word of God says that this was always Jirix; he just kept getting resurrected off-screen.
 * Qarr the imp has become The Watson to the Inter-Fiend Cooperation Commission.
 * MSF High: This is Donovan's role. Fortunately, he is also The Hero in training.
 * As Hark! A Vagrant|Hark, a Vagrant!] points out, Dr Watson does seem to get unfairly flanderized in most portrayals outside of the original Sherlock Holmes novels.
 * In Templar, Arizona, Ben is the Watson most of the time, because the work is partly about this weird town, but there are aspects of the alternate-historical universe familiar to Ben but not us; for this, there is a new Watson (Mesmer) with an even more sheltered upbringing.

Western Animation

 * The entire premise of Futurama is Fry ending up in situations that need to be explained to him because of the thousand years that went by without him. Holy crap, there's a theme park on the moon!? Hilariously, on multiple occasions a new character will be thawed out (Fry's ex-girlfriend and That Guy from The Eighties) and become Fry's Watson, which not only demonstrates his considerable ability to acclimatise (read: there's still TV and beer, so he's just dandy), but also gives him a chance to show how little he retains of what he's learned.
 * Originally, the creators envision the show being about Fry's difficulties adapting to the future. They were surprised at how quickly he adapted, so they instead started to focus on Fry being stupid instead. Watching an episode from the first season then one from the most recent season, there is a clear difference in both the plots and Fry's attitudes.
 * Gus Griswald from Recess.
 * In the My Little Pony Friendship Is Magic episode "MMMystery on the Friendship Express", Pinkie Pie tries to investigate who sabotaged a cake she was guarding, and forces Twilight Sparkle (normally The Smart Guy) into the role of "my lowly assistant who asks silly questions with obvious answers." When Pinkie's methods (which largely consist of making wild, baseless accusations) prove ineffective, Twilight manages to get Pinkie to switch roles. Once Pinkie starts to understand the importance of getting all the facts, they switch again so she can solve the mystery of who ate all the other desserts on the train.

Multiple media

 * Any human in Transformers ever.
 * #4 of Cracked.com's 4 Realizations That Will Ruin Science Fiction for You is that science fiction needs a "straight man" to whom the setting's rules are explained.