In 1992, Sherwood became a recurring performer for three seasons of the British improvisational comedy television show "Whose Line Is It Anyway?". He was the only actor from the Los Angeles auditions to make it to the cast. Starting in 1998, he was a regular cast member for seven seasons on the American version of "Whose Line Is It Anyway?" which was produced by and aired on the American broadcaster ABC. The American version was hosted by comedian Drew Carey. Sherwood later made a guest appearance in three episodes of Carey's sitcom "The Drew Carey Show". He was also a producer and performer on "Drew Carey's Green Screen Show" (2005) and a performer on "Drew Carey's Improv-A-Ganza" (2011).