Leonard Williams (born West Derby, Liverpool, Lancashire 1914 - died London 15 November 1962) was an English actor. He was best known for playing Sergeant Percy Twentyman on the police television series Z-Cars. According to Brian Blessed he was "the joker of the cast", who spent his time on set making his colleagues laugh.
Williams also played the characters of Theodore Craythorpe & Harry Whittle in the BBC radio comedy series The Clitheroe Kid. He also made regular appearances opposite Harry Worth on television. He died of a heart attack at his flat in Lexham Gardens, Kensington. He was father to two children: Leon & Marianne.