Richard Sean Diplock (born 7 May 1965) is a Welsh former rugby union international.
Born in Ebbw Vale, Diplock was educated at Glan Afan Comprehensive School.
Diplock, who is a steelworker by profession, played his rugby union as a winger and represented Wales Youth. His only Wales cap came in a loss at home to Romania in 1988. He competed mostly for Aberavon and Bridgend at club level, with a stint too at Sydney club Drummoyne, before retiring from rugby at the age of 35.