William Delme Thomas (born 12 September 1942) is a former rugby union player who became one of Wales' best known rugby players in the 1960s and 1970s. He joined Llanelli RFC in 1961 and was the team's captain when they won the league in the 1972–73 season and was also the captain when Llanelli beat a touring All Blacks team in 1972. He is remembered for his emotional speech given to his teammates before this game. He played lock forward.