Autism in Fiction
TV
Big Bang Theory: Basically all main characters except Penny. This would include Sheldon Cooper (the strongest case for ASD in the series, with very heavy Autistic Narcissism and Obsessive Compulsive Disorder included), Leonard Hofstadter, Howard Wolowitz, Rajesh Koothrappali (with Social Anxiety Disorder, common as comorbid condition in ASD), Leslie Winkle, Bernadette Rostenkowski-Wolowitz (a bit of Autistic Narcissism included), Amy Farrah Fowler, Stuart Bloom, Barry Kripke (with Speech impediment found in many Autistics), Beverley Hofstadter (reminds me of a very good friend, very Pedantic) and Lucy (also with Social Anxiety Disorder).
Boston Legal: Jerry "Hands" Espenson. An Attorney at the firm, Crane, Poole and Schmidt. Jerry also has Tourette's Syndrome, a common feature in Autism.
Galactica 1980: Dr. Zee, the genius advisor of Admiral Adama.
House: Dr. Gregory House, clearly Autistic traits with Autistic Narcissism and Autistic Malice. Diagnosed by his friend Dr. James Wilson. House is also based on the Sherlock Holmes character (see Sherlock).
Monk: The Deffective Detective Adrian Monk who is clearly Autistic with clear signs of Hyperlexia, Synesthesia, Phobias and savantism. Also with comorbid conditions of Social Anxiety, Depression and Obsessive Compulsive Behaviour. Adrian's brother is also Autistic (with Obsessive Compulsive Disorder, Hoarding and Social Anxiety Disorder). Some series regulars are also clearly Autistic, such as Harold Krenshaw and Kevin Dorfman
My Name is Earl: Randy Hickey, the brother of the main character Earl. At one stage Earl stated that a docter diagnozed Randy as "artistic".
Suzelle DIY: Suzelle, the DIY Queen of South Africa has mannarisms that is indicative of Autism, with an obsessive interest in collecting Do It Yourself tips.
Sherlock: A modern take on the classic Sherlock Holmes character. The character of Sherlock Holes may call himself a High Functioning Sociopath, but it is clear that he is Autistic. How else would he be able to solve all his cases. Some scences in the series show how Sherlocke Holmes use synesthesia to solve riddles).
Star Trek: The Original Series: Mr. Spock, the First Officer of the USS Enterprise. Throughout the whole Star Trek franchise, all Vulcans could be classified as having Autistic traits.
Star Trek: The Next Generation: Data, Reginald Barcley,
Star Trek: Deep Space Nine: Odo, Grand Nagus Rom.
Star Trek: Voyager: Seven of Nine, Reginald Barcley,
Star Trek: Enterprise: Commander T'Pol, the Vulcan First Officer and Chief Science Officer of the Enterprise.
Star Trek: Discovery: This series is still in the pre-production phase, but as is evident in the previous series' of Star Trek, there will indeed be characters with Autism traits.
Stargate SG1/Stargate Atlantis: Dr. Rodney McKay
Riptide: Murray Bozinsky, the Riptide Detective Agency's scientific and technical genius.
Movies
Office Space: Milton Waddams, who is constantly bullied by his boss, Mr. Lumbergh and other colleagues. The movie is also a good representation of what goes on in an office.
Carrie: Carrie White, a bullied teen who finds out that she has supernatural powers and uses it to kill her class during the prom. The movie is basically an allegory of Autism and their strengths that seems to be superhuman.
The Fifth Estate: Julian Assange (Based on the life of the founder of Wikileaks)
The Imitation Game: Alan Turing (Based on the life of the inventor of the Computer, and the man who cracked the Nazi Enigma Code)
The Hangover Trology: Alan Garner, with clear signs of Autistic Narcissism.
Forest Gump: Buford Bubba Blue, Forest Gump's friend during the Vietnam War who is obsessed about shrimps.
Hot Pursuit: Officer Rose Cooper, who is obsessed about her work and police procedure. Rose speaks in a very pedantic manner, common in Autism. She also takes some comments literally, as in the case of a young man shouting that he is "... riding shotgun", believing that he has a shotgun and then tazes him.
Hitchhikers Guide to the Galaxy (movie): Ford Prefect.
Back to the Future Trilogy: Doc Emmet Brown.
Fanboys: Windows, Harold, Eric, Linus, Zoe and Admiral Seasholtz.
Paul: Graeme Willy and Clive Gollings. (Cameo by Steven Spielberg as himself).
Napoleon Dynamite: Napoleon, Skip, Deb and Pedro.
The Accountant: Christian Wolff. Described as a human calculator.
Wikipedia Movie List
Change of Habit (1969): Amanda
Run Wild, Run Free (1969): Philip Ransome
The Boy Who Could Fly (1986): Eric Gibb
Rain Man (1988): Raymond "Ray" Babbitt. Based on the life of Kim Peek.
Backstreet Dreams (1990): Shane Castello
Family Pictures (1993): Randall Eberlin
House of Cards (1993): Sally Matthews
Cries from the Heart (1994): Michael Barth
David's Mother (1994): David Goodson
Henry & Verlin (1994): Henry and Verlin
Silent Fall (1994): Tim Warden
The Innocent (1994): Gregory White
Under the Piano (1995): Rosetta Basilio
Mercury Rising (1998): Simon Lynch
Nightworld: Lost Souls (1998): Meaghan Robinson
Down in the Delta (1998): Tracy Sinclair
Molly (1999): Molly McKay
Bless the Child (2000): Cody O'Connor
Les Diables (2002): Chloe
Biola Tak Berdewai (2003): Dewa
Dreamcatcher (2003): Duddits
Killer Diller (2003): Vernon Jackson
Midwinter Night's Dream (2004): Jovana
Somersault (2004): Karl
Miracle Run (2004): Steven and Philip Morgan
Marathon (2005): Cho-won
Raam (2005): Rama Krishna
Mozart and the Whale (2005): Donald Morton and Isabella Sorenson
Breaking and Entering (2006): Bea
Snow Cake (2006): Linda Freeman. Sigourney Weaver consulted Autistic Adult, Rose Blackburn.
Ben X (2007): Ben
P.S. I Love You (2007): Daniel Connelly
Imagination (2007): Anna Woodruft
The Black Balloon (2008): Charlie Mollison
Dustbin Baby (2008): Poppy
God's Ears (2008): Noah Connelly
Dark Floors (2008): Sarrah
Chocolate (2008): Zen
Suzie (2009): Charles
City Rats (2009): Chris
Mary and Max (2009): Max Horovitz
Adam (2009): Adam Raki
Ocean Heaven (2010): Dafu
My Name is Khan (2010): Rizwan Khan
Fly Away (2010): Mandy
Quantum Apocalypse (2010): Terry Marshall
Burning Bright (2010): Alan Wheddon
Salmon Fishing in the Yemen (2011): Alfred Jones
Exodus Fall (2011): Dana Minor
Dr. Pomerants (2011): Yoav Pomerantz
Mabul (2011): Tomer Roshko
Extremely Loud and Extremely Close (2011): Oskar Schell
A Mile in His Shoes (2011): Mickey Tussler
Barfi! (2012): Jhilmil Chatterjee
Joyful Noise (2012): Walter Hill
The Story of Luke (2012): Luke and Zack
White Frog (2012): Nick Young
The Odd Way Home (2013): Duncan
Haridas (2013): Haridas
Season of Miracles (2013): Rafer
Alien Abduction (2014): Riley Morris
X-Y (2014): Nathan Ellis
Literature
Comics
DC Comics: Black Manta
Psi-Force: Johnny Do
With the Light: Raising an Autistic Child: Hikaru Azuma
X-Men: Legion