Reeson Wayne Shearsmith (born 27 August 1969) is a British actor, comedian, writer and magician. He was a member of The League of Gentlemen, with Steve Pemberton, Mark Gatiss and Jeremy Dyson. Jointly with Pemberton, he created, wrote and starred in the sitcom Psychoville and the dark comedy anthology series Inside No. 9. He had notable roles in Spaced and The World's End.

Shearsmith was born in Kingston upon Hull, East Riding of Yorkshire. He attended Andrew Marvell High School and then Bretton Hall College of Education, where he met Mark Gatiss and Steve Pemberton, fellow actors and comedians The League of Gentlemen began as a stage act in 1995, transferred to Radio 4 as On the Town with The League of Gentlemen in 1997, and arrived on television on BBC Two in 1999. The last saw Shearsmith and his colleagues awarded a British Academy Television Award, a Royal Television Society Award and the prestigious Golden Rose of Montreux. Following The League of Gentlemen, Shearsmith appeared in comedy programmes including Max and Paddy's Road to Nowhere as well as playing villain Tony in the Vic Reeves and Bob Mortimer comedy Catterick. He appeared in two episodes of the award-winning pop-culture comedy Spaced as Robot Wars-obsessed TA soldier Dexter, and played neurotic Doctor Flynn in hospital sitcom TLC alongside Alexander Armstrong. In 2014, Shearsmith and Pemberton returned to BBC2 with a new dark comedy series called Inside No. 9. Each episode of the anthology series takes place in a different 'No. 9' location. Shearsmith and Pemberton play various characters in the series and have also directed two of the episodes.[16] Also in 2014, he starred as Malcolm Webster in ITV drama series, based on a true story, The Widower.