Alvin Leon Williams (born August 6, 1974 in Philadelphia, Pennsylvania) is an American professional basketball player of the National Basketball Association. He played college basketball at Villanova University. The Portland Trail Blazers drafted him in the second round of the 1997 NBA Draft, and Williams began his career there before going on to play for the Toronto Raptors, joining them in 1998. He appeared in all 82 games for two straight seasons, in 2001-02 and 2002-03. After missing a third of the 2003-04 and the entire 2004-05 season with a knee injury, Williams re-joined the lineup at the start of the 2005-06 season. Unfortunately, the injured knee forced Williams back on the injured list after playing just one game that season.
On July 26, 2006, Williams was waived by the Toronto Raptors to make room for free agent guard Fred Jones. Reports said both the team and Williams had reached an agreement which resulted in the Raptors only having to pay half of Williams' remaining salary. Interestingly, Fred Jones was assigned Williams' #20 jersey number the next day.
On January 20, 2007, Williams signed a 10-day contract with the Los Angeles Clippers. He was not signed to a second contract after the first had expired after appearing in two games in limited action.