Seven of Nine?

Jonah Judah from Bojack horseman is very clearly autistic, but it’s never mentioned or even the source of any plot point. He’s just a regular character who happens to be autistic and has his own plot things and stuff.

Edit: misremembered the name

You want an autistically-coded sci-fi main character? The Murderbot Diaries have you covered.

The ones that come to mind:

• Captain Raymond Holt in Brooklyn 99
• Sheldon Cooper from the Big Bang Theory
• Mr Spock from Star Trek
• Gus Fring (maybe), Gale and Lydia from Breaking Bad
• Abed from Community

TV tropes has a few categories that cover this. They don’t limit the disorders to autism in most of the categories but the examples are more autism than anything else.

https://tvtropes.org/pmwiki/pmwiki.php/Main/DiagnosedByTheAudience

Egon Spengler and his grand-daughter Phoebe from the Ghostbusters franchise. The character of Ray Stanz also has some traits, no doubt assisted by the fact that actor Dan Ackroyd is autistic.

L from death note is a commonly given example I think.

I actually read this recently and I don’t think he’s autistic, but he was definitely written intentionally to show how a fairly confident, competent person (bordering on smug, but not quite) would struggle on prism.

Yeah definitely a thing. I’m not familiar with the book you had mentioned, but I know from the show Bones, the main character Temperance Brennan, is very autism coded. It’s never officially indicated, in the show, what her deal is when it comes to social interactions, but it’s been hinted on officially by staff and writers that she is autistic to some degree. It’s not a very accurate portrayal of high functioning autism, however it technically counts I guess?

Hank Hill from King of the Hill

I read Kyr in Emily Tesh’s “Some Desperate Glory” as autistic.

No experience with that book, but a lot of literature has autistim coded characters. Lot, well sort of, debate in the Warhammer 40k communities about a fair number of autism coded characters there. I can’t remember who all they’ve said since I avoid a lot of the conversations but if I remember right a fair number of Space Marines, and their ‘traitor’ brethren are ‘autistic’.

Autism coded characters are 100% a thing - I’d go a step further and say it’s possible for a character to be Autism coded without the author realizing. Ultimately, all characters are based on experience (either the writer’s own, or the experience of other writers they’re influenced by), and I think it’s fairly common for writers to draw on a particular archetype, inspired by someone they know or a character they’ve seen elsewhere, and implement that archetype without realizing that their inspirations (and hence their derivative creation) are autistic.

One of the most famous ones is Abed from the TV show Community, who supposedly wasn’t initially written to be autistic, but when everyone pointed out that he was it led the showrunner to realize he himself was probably on the spectrum as well.

I’ve seen people suggest that Peridot from Steven Universe is autistic coded as well (although I’m not sure it makes sense for her to be literally neurodivergent, since she is an alien rock and doesn’t have actual neurology).

I feel like I had a bunch of examples of characters who are autistic coded but not confirmed to be autistic, but they’re not springing to mind right now. I’ve thought about this before because a bunch of them are great characters that I resonated with before even noticing their autistic traits (or mine). Someone already mentioned Judah Mannowdog from Bojack Horseman.

Oh, I’ve seen people say Lilo from Lilo and Stitch is autistic coded, and I guess I can see it. Also, obviously Sheldon Cooper is a negative portrayal of autism that the creators will never admit is autistic because then they’d have to admit he’s a mocking caricature of autism.

There are some great characters from one of my favorite shows who I’m pretty sure are autistic, with differing presentations. But, while I’m happy to identify as a fan of that show, and happy to identify as autistic, I worry that identifying as both at the same time is playing into some negative stereotypes about both groups. But one of the characters is really into rocks and the other is really into kites. Iykyk.

I briefly googled autistic coded characters to try to refresh my memory, but have only included characters I have personally previously formed opinions about, since that seemed to be what you were asking for. But if you just want a bunch of discussions and lists, googling “autistic coded characters” will get you a lot of different takes.

In general I feel like autistic coded characters are often better representation than explicitly autistic characters, because when a piece of media explicitly labels a character as autistic, they can often lean into making Autism their only personality trait, or even make it a selling point of the entire work. Autistic coded characters have the luxury of being an actual person that happens to be autistic, instead of a walking billboard for the writer’s research on neurotypes.

Is autism coded characters a thing?

Short answer: Yes

Long answer:
rules:

• no autism diagnosis (excludes Sean Murphey)
• no possibility of autism ever suggested (excludes Gregory House and Regan from inside job)
• no alternate diagnosis (excludes Komi from komi can’t communicate who is canonically SAD not ASD)
• must demonstrate an autistic trait, though not necessarily the obvious one (Sprig is here because he experienced sensory overload in a cinama)
• no traits only shown in fanfiction considered (I don’t want to be here all day)
• have to be from a show I’ve watched and I personally have to see it (no Abhed from community, no Catniss Everdeen from hunger games)
• they don’t have to be good representation (so I don’t have to justify several of my choices most notably Sheldon or Beverly)
• no instances where the author obviously knew what they were doing when they created the character (excludes the Mitchells from the Mitchells vs the machines, but not sheldon because they fell into writing him like that by accident)
• being an excentric genius isn’t a sign of autism (excludes Albus Dumbledor)
• being an idiot savant isn’t a sign of autism (excludes Forrest Gump)

so in no particular order:

• Myne and Ferdinand from Ascendance of a bookworm
• The entire La clan from Apothocary Diaries
• Luna Lovegood from Harry Potter
• Several Stephanie Meyers protagonists including Bella Swan from Twilight, Wanderer of the stars from The Host and the one who keeps changing her name so it’s not worth keeping track of it from the Chemist
• L and Near from death note
• Lios from delicious in dungeon
• Mob from Mob Psycho 100 and Saitama from one punch man
• Saiki K from the disasterous life of Saiki K
• Akun from Aho Girl (also Yoshiko get’s an honorable mention for ADHD)
• Star from Star vs the Forces of Evil
• Mabel and Dipper from gravity falls
• Luz from owl house
• Marcy, Sprig and Polly from Amphibia
• Ferb from Phineas and Ferb
• Lilo from Lilo and Stitch
• Peridot and Lapis Lazuli from Steven Universe.
• Papyrus and Nabstabluk from undertale
• Abby from NCIS
• Spencer from iCarly
• Commander Spock from Startrek
• Captain Sam Carter, Dr Daniel Jackson and Thor from Stargate SG1
• Sheldon, Raj, Beverly and Amy from the Big Bang Theory
• A lot of spidermen, though it’s strongest in Penny Parker IMO
• Every robot ever put to screen who’s name isn’t Baymax
• Many, many aliens including some listed above

I have heard heard some people claim that Jernau Morat Gurgeh (from Player of Games by Ian M Banks) is probably autistic, but personally i think he’s more Ace-coded than anything else. Maybe you might think otherwise?

Personally I think a better example is Stafl-Preonsa Fal Shilde 'Ngeestra dam Crose, the Referrer from Consider Phlebas. She has a fixation on free solo climbing, and enough brainpower that supercomputers go to her for advice. I personally found the robot that was crushing on her to be super cute.