William Joseph Mosconi (; June 27, 1913 – September 17, 1993), generally known as
Willie Mosconi, was an American professional
pool (pocket billiards) player from
Philadelphia,
Pennsylvania. Between the years of 1941 and 1957, he won the
World Straight Pool Championship an unmatched fifteen times. For most of the 20th century, his name was essentially synonymous with pool in North America – he was nicknamed "
Mr. Pocket Billiards" – and he was among the first
Billiard Congress of America Hall of Fame inductees. Mosconi pioneered and regularly employed numerous
trick shots, set many records, and helped to popularize pool as a national recreation activity.