Swansea manager Brendan Rodgers has secured the defensive reinforcements he had targeted after completing the signing of Darnel Situ, subject to Premier League clearance.
The central defender, who can also play as a holding midfielder, arrives from Lens on a two-year deal with Swansea paying an initial fee of £250,000.
The 19-year-old, who has captained France from Under-16 up to Under-19 level, had also attracted the interest of Newcastle, where he spent time on trial, and Fulham, but elected to make the move to South Wales.
He told Swansea's official website: "I was told about Swansea's interest about 10 days ago and I have been researching the club ever since on the internet.
"I'm really excited about joining Swansea and the Premier League. I watch the Premier League on TV a lot back home and I am a big fan.
"There was interest from the likes of Fulham and Newcastle, but Swansea were the ones who wanted me the most and I am delighted to be here.
"I have met the manager and I am looking forward to working with him and gaining from his experience."