The 23-year-old arrived on Tyneside from L’OM 12 months ago, but headed back to the Stade Velodrome in January on loan for the remainder of the 2015/16 season.
Returning to the North-East this summer, Thauvin featured in four of United’s five pre-season friendlies and he leaves the Club having made 16 competitive appearances, five of which were starts, and scoring one goal.
Thauvin’s move sees him join up with former Magpies’ teammate Remy Cabella, whose own loan switch to Marseille has become permanent ahead of the 2016/17 campaign.