Terms were not disclosed, but league sources said the deal was worth between $11 million and $12 million.
Barnes tweeted the news Friday by first re-tweeting Chris Paul's announcement earlier in the week that Paul was staying with the Clippers. "RT @CP3: I'M IN!!! #CLIPPERNATION... I guess that makes two of us!! Lets get this.."
After signing a one-year deal for the veteran's minimum before the start of training camp this past season, Barnes enjoyed a productive year with the Clippers, averaging a career-high 10.3 points, 1.0 steals and 0.8 blocks per game. He also averaged 4.6 rebounds and 1.5 assists per game.
Barnes' production increased during the playoffs, when he averaged 11.8 points and 5.0 rebounds per game, including putting up 30 points and 10 rebounds in the Clippers' Game 6 loss to the Memphis Grizzlies in the first round.
It was always Barnes' intention to stay with the Clippers, but he was looking to make more money after being one of the most consistent players off the bench for the Clippers last season.
"I've been one of those guys the last three or four years that's always been a great bargain," he told ESPNLosAngeles.com. "I've played for the mid-level and have played well but have yet to see a payday. Not to say that I'm asking for the world, but I'm definitely looking for a salary increase."