Ex-World Cup winner and Barcelona defender Umtiti signs for Lille
"The great Sam is back," said LilleLille president Olivier Letang.
"It's a strong signal when a French world champion returns to Ligue 1".
The 29-year-old defender was released from his contract with Barcelona earlier this month, and had been expected to return to former club Lyon which he left in 2016 for the Spanish side.
"Returning to France, logically I thought of Lyon but in the end I chose to go to a club that wanted me," said Umtiti, who won the French Cup with Lyon in 2012 and two La Liga titles with Barcelona in 2018 and 2019.
After an injury-plagued four years, Umtiti was loaned last season to Italian club Lecce where he played 25 matches.
Despite repeated injuries Umtiti said he was "feeling good physically" and raring to go for Lille who finished fifth in Ligue 1 last season.
"I had a full season last year, even though I started playing in December," he said.
"I really want to be successful with Lille, if I am, other things will come with it, I don't worry about that."
Cameroon-born Umtiti was the hero of France's 2018 World Cup, scoring the only goal against Belgium in the semi-final, and remains hopeful for a return to the national side.
"I have already tasted the France team, experienced exceptional moments, obviously these are things that I want to relive.
"I know their qualities, I saw that this team lacked a bit of experience at times, but I will not be able to do everything alone."