Down these mean streets a man must go who is not himself mean, who is neither tarnished nor afraid. The detective must be a complete man and a common man and yet an unusual man. He must be, to use a rather weathered phrase, a man of honor. He talks as the man of his age talks, that is, with rude wit, a lively sense of the grotesque, a disgust for sham, and a contempt for pettiness.
A Seeker character frequently used in Detective Drama. A professional detective not directly affiliated with a police department in any official sense (although many will have contacts in the department, and it's not uncommon for members of this profession to have been either police officers or previously worked in law-enforcement, as many of the skill sets overlap), a Private Detective takes on cases that private citizens bring to them - however, whilst they aren't supposed to investigate crimes (which are official matters for the police, who often look dimly upon private detectives sticking their noses in - both in fiction and in real life), they usually find themselves knee-deep in murders, robberies and kidnappings by the end of the story. They may be doing this because the Police Are Useless and/or unconcerned about solving the case, meaning our detective is the only person who is actually willing or capable of solving it.
Although it's more common for a Private Detective these days to be treated as just one step away from the Amateur Sleuth (or often, particularly if seen from the point of view of the police, as rather sleazy bottom-feeders usually involved in some kind of criminal activity and frequently ex-cops kicked off the force for some kind of corruption), the classic Archetype of the Private Detective - and the one that has generally stuck in the mind of people when they think of the profession - is either the Great Detective or the Hardboiled Detective.
While the comparison with the Amateur Sleuth is common, in many ways the stories work the opposite ways. The Amateur Sleuth, such as Miss Marple, tend to cozy locked room mysteries, where everything starts complicated and uncertain, but slowly works its way down as a logic puzzle, with a tidy solution where the killer is unmasked. The Private Investigator tends to start simple, but as the investigation will unravel an ever more complicated plot, and the ending is rarely tidy. The killer may be unmasked, but larger problems tend to stay unsolved.
Vampire Detective Series often feature one as a protagonist, though of the immortal variant.
- Death Note: L.
- Rin Asougi of Mnemosyne is an immortal private detective who chucks knives at people, knows Waif Fu, and has a tendency to get mutilated/killed... a lot.
- Detective Conan Kogoro Mouri, Heiji, and main character Conan Edogawa/Shinichi Kudo
- One of them in Japan Inc finds out that a big union boss is a customer in an S&M club.
- Heironymous "Hip" Flask is a private eye and anthropomorphic hippo in the Elephantmen comics.
- From E-Man comes Michael Mauser. Just... don't call him Mickey.
- Judge Dredd spinoff The Simping Detective features Jack Point, a judge working undercover as a private detective. In clown gear. Simping is a fashion trend/sub-culture in Mega City One. The point of the trend is to look as stupid as possible so that people will bother to notice that you exist.
- German example: Nick Knatterton.
- Dwight from Sin City. His career comes to an end once he's wanted for murder, however.
- In the Sam & Max universe, the main characters are rather atypical private detectives (though they prefer the term "freelance police"), while their neighbor Flint Paper is a more stereotypical, two-fisted, Dirty Harry type.
- Two of the most famous roles of Humphrey Bogart form the Trope Codifier for the Hardboiled Detective variant: Sam Spade in The Maltese Falcon and Phillip Marlowe in The Big Sleep.
- A 1975 film The Black Bird is a comedy sequel to The Maltese Falcon with George Segal playing Sam Spade, Jr.
- Casey Affleck's character in Gone Baby Gone is an example of a modern PI.
- Kiss Kiss Bang Bang has fun with all the Film Noir tropes, this one included: Val Kilmer's character 'Gay' Perry Van Shrike is a hard-bitten, tough-talking, gun-slinging Private Detective who's also, well... gay. And considers his job very boring. And, at least until Harry and Harmony come into his life, isn't exactly dogged in his pursuit of justice.
- In Lethal Weapon 4, Leo Gets becomes a licensed PI. This garners much comedy for Riggs and Murtaugh.
Riggs: "Excuse me, private investigator? Could you investigate my privates?"
- Ace Ventura: Pet Detective
- Who's the black private dick, that's a sex machine to all the chicks?
- In The Big Fix, Richard Dreyfuss plays the most true to life private detective ever filmed. Like real private detectives, he spends most of his time on divorce cases and (mostly legal) corporate espionage and commercial investigations. For the movie he does deal with a murder, but there is no doubt it's the first one he's come across in years of detective work.
- Angel Heart has the memorable character of Harry Angel, an ordinary private detective who owes his soul to the Devil, apparently given a seemingly straight forward task to find a missing person who owes his client his soul... er, money, yes. He just owes him money. It turns out not to be quite so simple when it turns out the whole time he is the person he spent the movie looking for.
- In There's Something About Mary Ben Stiller plays Ted, a modern day private detective who is hired to stalk on the title character for a ex-lover from high school. Ted averts the honorable portion of the trope by going after Mary for himself.
- The works of Dashiell Hammett (The Maltese Falcon, Red Harvest, etc.) and Raymond Chandler (The Big Sleep, Farewell, My Lovely, etc.) in particular are often credited with creating and popularizing the Hardboiled Detective version.
- With Nick Charles as the more light-hearted version (although not as much as in the movies).
- Agatha Christie's Hercule Poirot is retired from the Belgian police force, emigrated to England during World War I, and became a Private Detective in London.
- Sherlock Holmes is often described as the 'first consulting detective', thus making this Older Than Radio. Private detectives existed prior to Holmes, and he claimed that being a "consulting detective" was something different:
"Well, I have a trade of my own. I suppose I am the only one in the world. I'm a consulting detective, if you can understand what that is. Here in London we have lots of government detectives and lots of private ones. When these fellows are at fault, they come to me, and I manage to put them on the right scent. They lay all the evidence before me, and I am generally able, by the help of my knowledge of the history of crime, to set them straight."
- John Taylor of Simon R. Green's Nightside books is a classic - if slightly skewed - example of a private eye.
- Joe Sixsmith, a character of crime fiction author Reginald Hill, subverts most of the basic Private Detective characteristics: a short, balding, middle-aged, black private eye from Luton, whose hobbies include singing in a choir and motor mechanics. His main talents are being a nice, sympathetic sort of guy, knowing when he doesn't know things, and tremendous serendipity.
- Robert B. Parker's Spenser is a modern, politically correct version of the type. If anything, he errs as far on the "sensitive" side of the "sensitive tough" archetype as Mike Hammer errs on the "tough" side.
- The titular character of the Joe Copp series, written by Don Pendleton (also the author of The Executioner series), is a private detective who used to be a cop.
- Mma Precious Ramotswe (in the The No. 1 Ladies Detective Agency series by Alexander McCall Smith) subverts almost all of this trope, being a kind and overweight Botswanan lady who solves everyday problems, like absconding husbands, by a sharp psychological perception, persistence and being able to win the confidence of others.
- Nohar Rajasthan from S. Andrew Swann's Moreau series of books is a down-on-his-luck PI... who just happens to be an 8'-tall humanoid tiger Super Soldier. Better Than It Sounds.
- The early Shadowrun novel 2XS has a noir-ish private eye story in Shadowrun's infamous Cyberpunk plus magic world.
- In L. Jagi Lamplighter's Prospero's Daughter trilogy, Mab's body was modeled after Bogart, and he acts as the company detective.
- Rex Stout's Nero Wolfe was a somewhat sedentary stay-at-home version of this; narrator Archie Goodwin did most of the legwork, and if they needed more legs they'd hire three other private investigators.
- In the children's mystery series, Trixie Belden, the title character and her bestfriend, Honey, plan on opening the Belden-Wheeler Detective Agency when they're older.
- This is how Harry Dresden makes his living, though he's really an Occult Detective.
- Kinsey Millhone is one.
- Angel started out as a private detective, before he made the transition from "supernatural crime" to "supernatural".
- Humorously parodied in the Canadian TV series Butch Patterson: Private Dick. Butch is given to internal monologues, wears a fedora everywhere he goes, refers to himself as a "Dick", and drinks very heavily...so heavily, in fact, that he's known to continually wet his pants and prematurely ejaculate. To make matters worse, he's also got a thing for prostitutes, a tendency to wake up in strange places after passing out drunk, and it's unlikely he'll ever live down that incident at the petting zoo. In spite of this, he's actually a very competent detective, and generally manages to solve the case, although he quickly blows whatever money he makes on pornography and whores.
- A somewhat early TV example: John Cassavetes' piano player turned "jazz detective" Johnny Staccato, in the eponymous 1959 show .
- Moonlight's Mick St. John started out as a private detective, before he made the transition from "supernatural crime" to "supernatural".
- An episode of NCIS has the team working with a private investigator. Gibbs expresses his contempt for the fellow by repeatedly referring to him as a "private dick," emphasis on the second word.
- Jim Rockford of The Rockford Files is a straight example. He's an ex-con (albeit innocent of the charges). He also edges the Affectionate Parody line.
- Magnum, P.I. is about one of those: from his contacts in the police to the monologuing, the trope fits him to a T... for Trope.
- Keith Mars (former cop) and Vinnie Van Lowe (stereotypical sleazeball) of Veronica Mars.
- In one episode of Married... with Children Al Bundy dreams that he is a noir-style private eye.
- Shotaro Hidari of Kamen Rider Double is a Private Detective. However he isn't as hardboiled as he likes to think he is, leading to his fellows referring to him as "half-boiled". Both major characters refer to themselves as "two detectives in one": Shotaro does the field investigations while his partner Philip (named after Philip Marlow) does the research back home. Prior to the two meeting Shotaro worked for another, much more hard-boiled detective whose death helps to kick off the events of the series.
- Simon and Simon: Rick and AJ Simon, brother PIs.
- Emerson Cod from Pushing Daisies. He would like nothing better than to be able to just have Ned get the pertinent facts from a corpse, and then collect the rewards in short-order, with as little effort for him as possible. He also primarily deals in cases where the death has been written off as an accident or the police themselves offer a reward for any valuable information related to a case.
- Gossip Girls Chuck Bass has one on speed dial. And that's not his only private investigator. His father also had a couple.
- Decoder Ring Theatre's Black Jack Justice is played straight, although there are two detectives, one male (Jack Justice) and one female (Trixie Dixon, Girl Detective), who take turns providing monologue.
- Guy Noir, Private Eye is A Prairie Home Companion's parody of the detective genre.
- Another parody example is Nick Danger, Third Eye from Firesign Theatre.
- Lewton, in Discworld Noir, both embodies and parodies this trope, due to the Disc's Theory of Narrative Causality; he doesn't know why being a private investigator means he has to wear a trenchcoat and fedora, but he's quite sure it does.
- Raidou Kuzonoha from Shin Megami Tensai: Devil Summoner 2: Raidou Kuzonoha Vs King Abaddon is sort of a cross between this and a Ghostbusters.
- Attention-seeking "Ace Detective" Luke Atmey in Ace Attorney, who is always just a step behind Phantom Thief Mask*DeMasque. Step ahead, actually. He's the one planning the heists and sending the thief the plans anonymously, so he both gets the items and makes himself look good.
- Despite being a defense attorney, Gregory Edgeworth is dressed like a stereotypical private detective in Ace Attorney Investigations 2.
- Kyle from Hotel Dusk: Room 215.
- Professor Layton is not this, but he's constantly mistaken for one.
- The Player Character from the Dark Parables games is a detective who specializes in solving mysteries related to fairy tales.
- Scott Shelby in Heavy Rain. Subverted when it turns out he's just posing as one in order to eliminate all the evidence because he is the Origami Killer.
- Detective Grimoire.
- In the online game Sleuth, you create and play one who can have a background you either design from the ground up, or you can choose preset backgrounds including an ex-detective disillusioned by the corruption in the system, a freelance reporter, a retired lawyer, or a reformed burglar, among others. Naturally, which background you pick affects which skills you begin with and how you approach the game.
- Problem Sleuth, Ace Dick, and Pickle Inspector, of Problem Sleuth. Then again, their style of investigation generally involves wearing trenchcoats and fedoras, being generally hard-boiled, and not doing any actual detection. And still, Pickle Inspector wears a bowler and doesn't put very much effort into being hard-boiled at all.
- In an Affectionate Parody, "Vikki Marlowe, Hard Boiled Dyke-Tective". A Meaningful Name; there are at least two authors and one character (the above-mentioned Philip) in detective fiction named "Marlowe".