Williams won a bronze medal as a member of the United States U18 team at the FIBA Americas U18 Championship in 2002. He was selected as a member of the USA Olympic team for the 2008 Olympics on June 23, 2008. The team went unbeaten on the way to winning back the gold medal after defeating 2006 World Champion Spain and living up to their "Redeem Team" moniker after missing out in the 2004 Summer Olympics. In 8 games in the 2008 Olympics, Williams averaged 8.0 points per game with 2.8 assists. Williams was one of three-point guards on the national team, alongside Chris Paul and Jason Kidd.