The Ligue 1 side have announced the signing of the Portugal international from Sporting Lisbon on a season-long deal, with a view to a permanent move
The 26-year-old Portugal international has only played for one club outside of the country during his career, in a year-long loan spell with Betis between 2010 and 2011.
He will now join the Ligue 1 side until summer 2014 with a view to a permanent transfer.
Lyon have also revealed they had to fend off interest from one of the star's former clubs, Porto, in order to land his signature.
Lopes made 14 league appearances for Sporting in the second half of last season, following a January move from Porto after his contract had expired.