Mvoto made 27 League One appearances on loan at Oldham last season and has been allowed to leave Sunderland at the end of his contract.
Huddersfield were linked with a move for the 22-year-old and Latics boss Paul Dickov is delighted to have brought Mvoto back to Boundary Park.
"This signing shows our intent because Big Jean was one of the best, if not the best, central defenders in our division last season," Dickov told the club's official website.
"I am over the moon to have signed him and Jean has shown a big commitment as he could have made more money going elsewhere. He had more lucrative offers from big clubs here and in France.
"Jean enjoyed last season here and the fans, office staff, management and players love him.
"He also believes in what we are trying to achieve and buys into that. When we told him about our plans he wanted to sign."