Payet pens deal with champions Lille
The 24-year-old leaves St Etienne having previously been courted by Paris Saint-Germain.
Payet will replace Ivorian Gervinho, who is likely to leave the club in the coming weeks.
The Ivorian has been linked with a move to Arsenal, after bagging 18 goals last season as the French side secured the Ligue 1 and French Cup double.
However, Lille President Michel Seydoux recently revealed that although Gervinho is keen to join the Gunners, no offer for the player has yet been made.
"We know that Gervinho is keen on Arsenal,” he told RMC. “For the moment, there has been simple contact, but we have not received a concrete offer yet."