Mr. Fixit

You want to reverse the polarity on your particle defibrillator? Better get it to Mr Fixit quickly.

It doesn't matter if Mr Fixit has never seen it before, has never seen anything like it before, is unfamiliar with its working principles or doesn't even know the stuff the box is made out of; Mr Fixit will be able to reverse engineer it in time for the big finale. He will often possess Machine Empathy, and can diagnose a broken gadget just by looking at it.

Overlaps with Mad Scientist, though not all Mr. Fixits are scientists or doctors; some are just avid tinkerers with a lot of free time. Compare Wrench Wench. Often overlaps with Gadgeteer Genius.

Unrelated to the Incredible Hulk, who used the alias "Mr. Fixit" in the late 1980s. And no, this page does not center around the fox in Richard Scarry's Busytown, either.

Anime and Manga

 * Bulma from Dragon Ball is a clear example. Able to build nearly anything with time and resources. She even took an alien scouter, and within a few hours or days, somehow changed its language from whatever alien space language it used, to Japanese!
 * It should be noted that the scouter did not display a language, only numbers, and deciphering a numbering system is actually very easy to figure out, relative to a language at least. Still impressive.
 * It's In the Blood: Bulma's son, Trunks, also has a knack for figuring out alien tech. He was able to repair the alien Robot Buddy Giru with little issue.
 * Leeron from Gurren Lagann anyone? Theoretically,
 * One MAN?
 * Yes, although he likes to act like he's a woman. But that's a different trope. Artenborough and Chubby who work with him are never shown to do anything scientific in particular.
 * Not that Leyte is much of a slacker either.
 * Presea  from Magic Knight Rayearth.
 * Wapourif from Simoun.
 * Yuusei Fudo from Yu-Gi-Oh! 5D's grew up in the slums of Satellite, but that didn't stop him from teaching himself mechanical, electrical, and computer engineering to the point where he could build his own D-Wheel from the scrap and spare parts tossed away by the people of New Domino... Twice. He also made a Duel Board (a skateboard with D-wheel capabilities) just by hearing about it from Rua...'in one night'!
 * Also Bruno, who on his first appearance managed to increase the power of the guys' D-Wheels where Yuusei couldn't.
 * Franky from One Piece. Usopp as well, especially before Franky joined the crew.
 * Winry, from Fullmetal Alchemist, shows the ability to fix most mechanical gadgets and break open locks (sealed with alchemy!) in addition to being a master of fixing automail.
 * Lionel "Pops" Racer. He's the one who designed and built the Mach 5.

Comic Books

 * In The DCU, the Justice League International often turned to Kilowog of the Green Lantern Corps for all their tech needs. The most extreme example was probably when he built the Club JLI resort on the island of KooeyKooeyKooey for Booster Gold and Blue Beetle in a matter of hours. In later incarnations of the team, this role was taken by Steel. Both characters were also Genius Bruisers.
 * That torch seems to have been passed to Badass Normal Mr. Terrific.
 * Taken to the extreme in Marvel Comics's Forge, whose mutant ability helps him build machines by simply imagining what they should do, rather than working out the pesky details.
 * Alan Moore's Promethea has an unusual example - Stan of the Five Swell Guys is clearly the Mr. Fixit of the team, but Marv claims to be the team genius. This subversion of Super-Hero Speciation becomes a plot-point when
 * Deaths Head's Sidekick Spratt is pretty competent with a toolbox, and rebuilt Death's Head after he was nearly destroyed by the Dragon's Claws.
 * Dino Manolis aka The Machinist of Stormwatch PHD excels at this. Too bad, he sucks at most everything else in life.
 * Herschel Clay,, from PS238. As the janitor for a school for metahumans, he's (obviously) a metahuman himself and has a love of tinkering. He's also implied to own Clay Industries, which sells most of the inventory, security doodads, and other components of the school and its security system. Exactly why the owner and main braintrust for a (presumably) multinational corporation works as a janitor at a school is anyone's guess.

Film

 * Fix-It Felix from Wreck-It Ralph and Ralph Breaks the Internet

Literature

 * Tinker Gnomes of Krynn. Of course it may not work as their non-gnome friends would hope.

Live Action TV

 * Professor Wickwire from The Adventures of Brisco County Jr..
 * Seamus Harper (The Engineer) from Andromeda.
 * Fred from Angel.
 * Chief Tyrol or Specialist Cally on Battlestar Galactica. Hell, even Starbuck gets into the tech mood now and then (see the Cylon Raider in the first season).
 * Warren from Buffy the Vampire Slayer might be an example of a villainous Mr. Fixit, while Willow was something of a Ms. Fixit.
 * Henry on Eureka.
 * The Doctor of Doctor Who has a tendency to be a Mr. Fixit, though he usually has seen, encountered, disassembled, built, and even created some of the items in question.
 * Not that that's a requirement. In one episode in new series 3 ("Utopia"), he fixes a rocket mere minutes after admitting he has no idea how it works. What's great is that he applies his own superior-in-normal-circumstances knowledge which gives him a "so obvious they overlooked it" answer (reverse the circuit).
 * Kaylee from Firefly is another Ms. Fixit, who demonstrated her prowess while having...relations...with her predecessor on Serenity.
 * Literally. She was on her back on the engine room floor and she saw what was wrong with the engine while the mechanic was preoccupied with being on top of her. It is implied that she made out with him specifically in order to get a chance to look at the engine of a real spaceship.
 * The Professor from Gilligan's Island made a freakin' car out of Bamboo Technology, which was actually spoofed in an episode of Veggietales.
 * Heather from Jericho. The term "Miss Fixit," was actually used as an insult by some members of the fandom who didn't like her. It somewhat backfired when the fans who did like her decided they liked the nickname.
 * Sayid from Lost.
 * Referenced by name in an episode of M*A*S*H where the nurses wake up Hawkeye (strange in itself given that he's the chief surgeon and dangerously overworked) to fix the heater in their tent. Turns out he's better at fixing people than heaters.
 * Sam Carter from Stargate SG-1 is a Ms. Fixit, as well as a Hot Scientist and The Squadette.
 * Rodney McKay from Stargate Atlantis.
 * Scotty from Star Trek: The Original Series.
 * Geordi La Forge from Star Trek: The Next Generation.
 * Miles O'Brien from Star Trek: Deep Space Nine. (being a character transplanted from Star Trek: The Next Generation, he only displays this same skillset on that show if something goes wrong with a transporter, and then only under Geordi La Forge's supervision)
 * Steve, the director of the "Top Gear Technology Centre," who became something of an Ascended Extra after the Britcar 24-Hour Race.
 * MacGyver.
 * Gibbs on NCIS with anything mechanical as showcased in "Power Down". If it's got electricity running through it, you're pretty much screwed. Let's not even think about computers. But has the power gone out and do you need to make copies with a machine no one has used or heard of in hundred years? Gibbs's got your back.
 * That's okay though, if it does have electricity, odds are both McGee and Abbey are capable of fixing it.
 * Luis and Maria on Sesame Street.
 * Red Green of The Red Green Show is something of a subversion. He fancies himself a practical Mr. Fixit, but his duct-tape reinforced Rube Goldberg inventions only work about half the time.

Tabletop Games

 * Nockers from Changeling: The Dreaming. They've go a knack for all things mechanical, and can fix broken machines by giving them a good hard thump or scowling and telling them off.
 * Some of the character types from other World of Darkness settings were also a dab hand at smash repairs, including Sons of Ether from Mage: The Ascension (who think they're doing Science rather than magic) and Glasswalkers from Werewolf: The Apocalypse  (who could talk to the spirits of machines).
 * In Changeling: The Lost, the Wizened often take on this role. They have access to Contracts that allow them to make a hovercraft out of a lawnmower and an inner tube.
 * In Traveller Sword Worlders have a great admiration for this. They make machines specifically to make them easy for a Determined Homesteader to tinker with.

Video Games

 * Anything at all break down in the Gears of War world for Delta Squad? Damon Baird's on it, with a growl, and a sarcastic comment about how much you guys suck at fixing things. Seriously, this guy basically repairs everything in the game. And then gives you lip about it. If he weren't so funny, (and your allies weren't immune to friendly fire) he'd probably have eaten a shotgun by now.
 * Anyone else notice that he looks like a bulked up version of Cid Highwind?
 * Bao-Dur in Star Wars: Knights of the Old Republic II. The player character in both games can become one as well, if his/her "Repair" skill is high enough.
 * Eddie Riggs, as the ultimate roadie can make and fix any stage equipment given the time and resources.
 * Slippy Toad in the Star Fox games.
 * Lucca in Chrono Trigger, as she single-handedly fixes a robot made with distant future technology the first time she sees it.
 * The Wing Commander games have a long series of Mr Fixits, in the form of the various crew chiefs that keep your fighter flying sometimes via the combined magics of Duck Tape and strong language. Nicknames for these folks include "Sparks" and "Pliers".
 * Jeff from EarthBound, all you needed was a place to sleep for the night and he could turn your Broken Iron into a Slime Generater.
 * Homeworld is one of the worst offenders regarding this trope. Within minutes of encountering an enemy vessel you've never seen before, you are informed that your own research team is ready to build an identical ship. Even when the ship in question is a millions-year old Precursor machine that's been lost to time, your trusty Hiigaran scientists can quickly devise countermeasures to them and even reverse-engineer them to produce copies.
 * "Mr. Fixit" from Constructor is an inversion: he's a cowboy builder who the player can send to sabotage the opposition's houses by "repairing" the plumbing, electrics or gas.

Web Animation

 * Sarge from Red vs. Blue. Lopez and Tex have good (if not better) mechanical skills too, but Sarge takes home the trophy for the way in which he goes about his repairs, such as somehow repairing a jeep without any tools or spare parts. Or better yet, rebuilding Simmons as a cyborg and using the leftover body parts to heal Grif after he was run over by a tank.

Web Comics

 * Any of the Sparks from Girl Genius.
 * Double Subverted all the time, as they often have their projects explode several times in the building progress. Notably, Agatha had a coffee maker she was working on explode, but went on to finish the coffee maker so well that it makes perfect coffee.
 * Tedd in El Goonish Shive graduated from this into a Mad Scientist.

Web Original

 * At the Super-Hero School Whateley Academy in the Whateley Universe, there are dozens of such kids. The mutant powers 'gadgeteer' and 'deviser' basically give a person this kind of power. Some are better at building their own devises, and some are better at working on others' gadgets. The side character codenamed Belphegor is excellent at taking other gadgets and devises and adapting them to his needs. However, he tends to steal other people's stuff before doing the adaptation bit.

Western Animation

 * Donatello from Teenage Mutant Ninja Turtles.
 * Grampy from the Betty Boop cartoons.
 * Rhinox from Beast Wars manages to create a device for "Extracting Metaphysical Essence from some alien probe." when Rattrap tells him to. Of course he isn't sure it'll work, but it does.
 * Subversion: Darkwing Duck. Drake Mallard repeatedly calls himself this in "Dry Hard," but there's little evidence to support it—until the ending sequence.
 * Gyro Gearloose (pictured above) from DuckTales (1987) and various Disney comics.
 * Fixit from Teen Titans. Not only can he fix anything, but he chose the name "Fixit" for himself.
 * Mr. Fixit the Fox from The Busy World of Richard Scarry.
 * Tracy, the gorilla from Filmation's Ghostbusters.
 * Wildcat from Tale Spin.

Real Life

 * Noah Antwiler of The Spoony Experiment fame got an Atari Jaguar to work by constructing a monstrous amalgamation of technology.