Aaron Williams (born October 2 1971 in Evanston, Illinois) is a professional basketball player currently with the New Orleans/Oklahoma City Hornets of the NBA.

He was undrafted after a college career at Xavier University, and has played for the Utah Jazz, the Milwaukee Bucks, the Denver Nuggets, the Vancouver Grizzlies (now the Memphis Grizzlies), the Seattle SuperSonics, the Washington Wizards, the New Jersey Nets, and the Toronto Raptors.

In 2000-01, Williams posted his best numbers as a pro, playing all possible 82 games while averaging 10.1 points and 7.2 rebounds per game, but also had the dubious distinction of leading the league in total personal fouls committed, with 319 (an average of 3.89 fouls per game).

On January 31, 2006, he was traded by the Raptors to the Hornets in exchange for two second-round draft picks.

His most common nickname is "A-Train".