Clifford Charles Devlin Thorburn (born January 16, 1948) is a Canadian retired professional snooker player.
Nicknamed "The Grinder" because of his slow, determined style of play, he won the World Snooker Championship in 1980, making him the first world champion in the sport's modern era from outside the United Kingdom.
He remains the only world champion from the Americas.
He was runner-up in two other World Championships, losing to John Spencer in the 1977 final and to Steve Davis in the 1983 final.
During his second-round encounter with Terry Griffiths in 1983, Thorburn became the first player to compile a maximum break in a World Championship match.
Thorburn's other notable achievements include holding the number one ranking during the 1981/82 season and winning the prestigious invitational Masters three times, in 1983, 1985, and 1986, which made him the first player to win the Masters more than once and the first to retain the title.
He retired in 1996 and was inducted into Canada's Sports Hall of Fame in 2001.