Mouhamadou Dabo has ended his 15-month spell at Sevilla, with the former St Etienne defender returning to France with Lyon.
Dabo, 24, has signed a four-year contract with Les Gones and moves for a fee of €1 million, with a further &euro800,000 in possible add-ons.
In a statement on their website, Lyon said the deal was likely to accelerate the departure of Lamine Gassama before the transfer window closes.
"Aged 24, Mouhamadou Dabo is a versatile player who can play on both sides of the defence,'' the statement said. "His arrival strengthens the defensive section of the team and anticipates the likely departure of Lamine Gassama.''
Born in Senegal, Dabo moved to Saint Etienne's youth academy at the age if 14 and went on to play for the senior team for five years before moving to Sevilla last May.
The France Under-21 international played 24 La Liga games last season.