The 25-year old Ivorian-born Belgian forward arrives at the Liberty Stadium with experience in Belgium, France and Spain and is looking forward to slotting into Michael Laudrup's line-up.
"This is a great opportunity for me and I'm happy to be here," he told the club's official website.
"I know a few of the players here, and I already know that Swansea is a family club that will suit my style of play.
"To play in the Premier League is a dream, and also to play under Michael Laudrup is fantastic for me.
"I am looking forward to starting training and meeting the squad, and then I want to show everyone what I can do."