The 10-time NBA All-Star guard, 33, has sat out the 76ers’ first three games of the season amid his feud with Philadelphia president Daryl Morey.
Harden called Morey a “liar” in an interview after reports the 76ers had ended talks about trading him.
The deal also includes the trade of 76ers duo P.J. Tucker and Filip Petrusev in exchange for Clippers players Nicolas Batum, Marcus Morris, Robert Covington and Kenyon Martin.
The Clippers confirmed the deal on Wednesday after Harden sparked controversy when he threatened to strike by refusing to play for the 76ers over their refusal to trade him.
Harden had expressed his desire to join the Clippers to partner with Kawhi Leonard and Paul George, as well as his former teammate Russell Westbrook, and said in August he would not play for the 76ers while Morey remained in charge.
He was fined $100,000 (£82,556) by the NBA for the comments and the league said: “The league’s investigation, which included an interview of Harden, confirmed that these comments referenced Harden’s belief that the 76ers would not accommodate his request to be traded.”
Talks between the 76ers and the Clippers broke down because of the demands set by the 76ers.
Morey was general manager of the Houston Rockets when Harden spent more than eight seasons with the franchise before moving to the Brooklyn Nets.
The pair’s relationship was a key factor in Harden moving to Philadelphia in a trade which sent Ben Simmons to the Nets.Harden helped the 76ers, alongside reigning NBA MVP Joel Embiid, to last season’s Eastern Conference semi-finals, where they lost to rivals Boston Celtics after blowing a 3-2 lead in the series.
He led the NBA in assists last season at 10.7 per game, while averaging 21 points and 6.1 rebounds.
The 2018 NBA MVP, who began his NBA career with the Oklahoma City Thunder in 2009, went to school in California around 21 miles away from the Clippers’ home venue.