Clifford Charles Devlin Thorburn 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, defeating Alex Higgins 18–16 in the final to become the first world champion in the sport’s modern era from outside the United Kingdom.

Thorburn was runner-up in two other World Championships, losing 21–25 to John Spencer in the 1977 final and 6–18 to Steve Davis in the 1983 final. One of his most celebrated moments came during his second-round encounter with Terry Griffiths in 1983, when he became the first player to compile a maximum break in a World Championship match. He was the second player, after Davis, to make a televised 147 break in professional competition.

His other notable achievements include holding the number one ranking during the 1981–82 season and winning the invitational Masters three times, in 1983, 1985, and 1986. This made him the first player to win the Masters three times and the first to retain the title. He retired from the main professional tour in 1996 and was inducted into Canada’s Sports Hall of Fame in 2001.

Thorburn subsequently competed in Snooker Legends events and on the World Seniors Tour, winning the 2018 Seniors Masters at the Crucible Theatre at age 70. On 5 January 2022, shortly before turning 74, he played his last competitive match at the 2022 UK Seniors Championship.