Keith Kelvin Deller (born 24 December 1959 in Ipswich, Suffolk) is an English retired professional darts player, who won the Embassy World Professional Darts Championship in 1983 and Unipart British Professional Championship in 1987.
He was the first qualifier ever to win the championship and remains one of the youngest champions in history.
For his world championship win, Deller used 18-gram spring-loaded darts, later banned for tournament play but now legal again.