Williams signed with the
Indiana Pacers July 6, 2006. Williams scored 13 points in his NBA debut against the Chicago Bulls on December 11, 2006. On October 10, 2008, Williams was traded to the
Dallas Mavericks for
Eddie Jones, two first-round draft picks and cash. On January 11, 2010, the Mavericks traded him and
Kris Humphries to the
New Jersey Nets for
Eduardo Nájera. Four days later, the Nets waived Williams. On September 23, 2010, the
New York Knicks signed Williams to a one-year contract. Williams had his best season with New York, playing a key role off the bench for the team as the Knicks reached the 2011 NBA playoffs. On December 15, 2011, the
New Jersey Nets signed Williams to a two-year contract, beating the offer made by the New York Knicks. On March 15, 2012, the Nets traded Williams,
Mehmet Okur, and a
2012 first-round draft pick to the
Portland Trail Blazers for veteran small forward
Gerald Wallace. Williams never appeared in a game for Portland. In early 2013, Williams joined Guangzhou Liu Sui for the 2013
NBL season. On September 3, 2013, Williams signed with the
Los Angeles Lakers. He was waived on January 7, 2014, the deadline before his contract would become guaranteed. The Lakers had injuries to guards
Kobe Bryant,
Steve Nash,
Steve Blake,
Jordan Farmar, and
Xavier Henry, and wanted to free up Williams' roster spot and salary in the event they later need another replacement at guard. On January 27, 2014, Williams was acquired by the
Los Angeles D-Fenders of the
NBA D-League. On February 6, 2014, he re-signed with the Lakers to a 10-day contract. He did not sign a second 10-day contract with the Lakers after his first 10-day contract expired. On February 19, 2014, he was re-acquired by the D-Fenders. On August 1, 2014, Williams signed with the
Miami Heat, rejoining former Pacers teammate
Danny Granger. On February 19, 2015, Williams was traded to the
New Orleans Pelicans in a three-team trade involving the
Phoenix Suns. Three days later, he was waived by the Pelicans. On February 24, 2015, Williams was claimed off waivers by the
Detroit Pistons. On June 11, 2015, Williams was traded, along with
Caron Butler, to the Milwaukee Bucks in exchange for
Ersan İlyasova. However, he was later waived by the Bucks on June 30, 2015. In October 2017, Williams joined the
Iowa Wolves in the
NBA G League. On January 21, 2019, Williams was reported to have joined the
Al-Riffa of the
Bahraini Premier League. == Personal life ==