Buxton's first television appearance was in an episode of Channel 4's Takeover TV, as a man called "Louise" dressed as a Klingon, complaining about Star Trek: The Next Generation being taken off the air. In 1995, he hosted the show itself, and following this he and Joe Cornish, along with World of Wonder, created The Adam and Joe Show for the same channel. It ran for four series. In 1999, The Adam and Joe Book, a spin-off book written by Buxton and Cornish, was published. Buxton co-wrote and acted in the Channel 4 mini-series The Last Chancers, broadcast in December 2004. In 2005 he moved from screen to stage, performing character-driven comedy at the 2005 Edinburgh Festival, with a show entitled "I, Pavel", for which he grew a large beard. He continues to work as a stand-up Comedian – appearing primarily at London venues – and still has a beard.

In November 2007, Buxton recorded the video for "Jigsaw Falling into Place" for British band Radiohead, which was the first single from their album In Rainbows. The concept of the video involved each member of the band wearing bicycle helmets with cameras attached, shooting video of the band members' faces.

In January 2010, he appeared in the BBC2 comedy The Persuasionists. He has taken part in a number of major films, including his aforementioned performance in Hot Fuzz, as well as appearing in the film Stardust, deputizing for Noel Fielding, who was ill at the time of production. He also featured in the film Son of Rambow as a Teacher. He has released a number of popular videos on YouTube, and was commissioned to produce a pilot programme for the BBC based around work of this kind. This was broadcast as MeeBOX on BBC Three in June 2008, but a full series was not commissioned. He also guest starred in the 2011 film "The External World" by David O'Reilly.

In July 2012, Buxton appeared in a TV version of his popular tour "Bug" on Sky Atlantic, entitled "Adam Buxton's BUG", Buxton narrated "Francis and Bunty", a short story used to front the 2009 "Best Writer in the Universe" short story competition, on The Story of Egmo podcast. He is also the narrator of some of the titles available on the Ladybird Classic Me Books iPad app, including Goldilocks and the Three Bears and Three Little Pigs. He has since narrated several other titles on the Me Books app such as 'The Great Explorer', 'The Brave Beast' and 'The Lonely Beast' by children's Illustrator and author Chris Judge. He also appeared in the Doctor Who audio drama The One Doctor by Big Finish Productions, and has taken other comedy roles on productions for BBC Radio 4.

Buxton has made appearances on Have I Got News for You, Never Mind the Buzzcocks, The IT Crowd, Don't Watch That, Watch This and Look Around You among others. He was also a panellist with Jonathan Ross for the Big Fat Quiz of the '80s. He appeared in the video game Lego City Undercover for Nintendo's Wii U. In 2014 and 2015, Buxton guest starred in several episodes of the comedy gameshow mash-up 8 Out of 10 Cats Does Countdown. In 2015 Buxton became the voice of Messy for children's TV animation Messy Goes to Okido which aired on 7 September 2015 on CBeebies. Since September 2015 Buxton has produced The Adam Buxton Podcast in which he talks to other people, usually comedians. The first series went out weekly in 2015 before a Christmas episode with Joe Cornish, in the style of their BBC Radio 6 show. Series 2 commenced in April 2016. Guests have included Louis Theroux, Jon Ronson, Caitlin Moran, Michael Palin and Joe Cornish.