The outspoken midfielder moved to the Ligue 1 club last year and has made 22 league appearances in a successful season for the side as they secured Champions League football with a win in their last game.
Barton cited the negative media coverage directed towards him in England as a reason behind his intention to see out his career in France, with the 30-year-old claiming he will 'never forget' the opportunity Marseille gave him.
"I'm truly happy here, it's a place where I'd like to be for the rest of my career, as long as Marseille want me," he told RMC Sport.
"They gave me an opportunity when everyone was very negative about me in England. I'll never forget that."
Marseille's 2-1 victory over Toulouse also ensured Barton's side's extremely remote chance of winning Ligue 1 are kept alive, though PSG could dash those hopes with a win over Lyon on Sunday.