The 21-year-old has signed a four-year deal and joins for a fee, according to media reports, of four million euros (£3.4 million).
"We've watched him all along the last season. He's young but already has a great experience in the Ligue 1 and has a big potential," Monaco's technical director Ricardo Pecini told the club's website.
Ambitious Monaco, regarded as the main challengers to champions Paris St Germain next season, will have to overcome a two-point deficit after they were sanctioned following violent incidents by fans during their Ligue 2 title celebrations.
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