Keir David Peters Gilchrist (/ˈkɪər ˈɡɪlkrɪst/;[1] born 28 September 1992) is a Canadian actor and musician. On television, he portrayed Marshall Gregson on the Showtime comedy-drama United States of Tara (2009–2011) and headlined the Netflix comedy-drama Atypical (2017–2021). His film roles include the comedy-drama It's Kind of a Funny Story (2010) and the supernatural horror It Follows (2014). Outside of his acting career, Gilchrist is the vocalist of grindcore band Whelm and death metal band Phalanx.[2]
Gilchrist was born in Camden Town, London,[3] to Canadian parents Catherine (née Peters) and Ian Gilchrist.[4][5] His maternal grandfather was banker, economist, and politician Douglas Peters, and his uncle is economist David Wilfrid Peters.[6][7] Gilchrist spent his early years in London, before relocating to Boston, Massachusetts, during his childhood,[8] then to New York City, before finally settling in Toronto, Ontario.
Gilchrist attended the Annex Children's Theatre. Gilchrist's first significant television role was that of Josh McKellar on Fox's short-lived television sitcom The Winner, which aired in 2007. From 2009 until its ending in 2011, Gilchrist co-starred as Marshall Gregson, the son of the lead character, on the Showtime comedy-drama series United States of Tara.[9]
In 2009, Gilchrist won the lead role of Craig Gilner in the film It's Kind of a Funny Story, which premiered at the Sundance Film Festival in January 2010.[10]
In 2014, Gilchrist co-starred in the film It Follows.
In 2015, he played the lead role of Daniel Austin in the film Dark Summer,[11] starred as John Lovett in The Stanford Prison Experiment and William in Len and Company, and had a role in the short drama film Share.[12]
In 2016, he co-starred in the film The Good Neighbor.[13]
In 2017, he starred in the film Heartthrob as Henry, directed by Chris Sivertson. In August of that year, he starred as Sam Gardner, a teen on the autism spectrum who is ready to have a girlfriend, in the Netflix comedy-drama Atypical. He continued with the role for four seasons until the show concluded on 9 July 2021.