John Spencer (born 18 June 1935) is a retired English snooker player who dominated the game in the 1970s along with Ray Reardon.
Snooker was in decline during Spencer's youth, and he did not turn professional until his early 30s, when interest in the game started to revive. He first won the world championship in 1969, and went on to win a total of three times, the last of which was the historic inaugural event at the Crucible Theatre in Sheffield in 1977. He never reached the top of the world rankings, always being eclipsed by his friend and rival Ray Reardon.
In January 1982, Spencer was Steve Davis's opponent when he made a 147 at the Lada Classic tournament in the Assembly Rooms, Derby. Ironically, Spencer had himself made a 147 at a televised event several years earlier, but the cameramen were on their tea break and the table and ball set were not at the correct standard.
Spencer was the first player to use a two-piece cue.
Spencer was also a commentatator on snooker for television for many years, and was chairman of the WPBSA for six years.
He retired from snooker suffering from myasthenia gravis (double vision) in 1985. He has recently been diagnosed with stomach cancer but has recently done a parachute jump. He is also about to publish a book.