The Cameroon international was unveiled at a news conference on Wednesday where he said he is looking forward to getting going at his new club.
The 26-year-old signed a four-year deal with French Ligue 1 side Lyon after his contract with Lyon’s French rivals Marseille came to an end at the end of the season.
He passed a medical examination Monday evening and joins the club on a contract until June 2020.
Nkoulou vehemently admitted that he has also held discussions with Italian Serie A side Roma.
“I spent five good years at OM, I was out of contract and it was time to turn the page.”
“I come with a lot of ambition and pride. I’m here because Lyon will allow me to grow and move forward
“Five years ago I chose Marseille rather than Lyon because of [the then coach] Didier Deschamps – but now destiny wants our paths to cross again and that’s important.
“I need to feel loved and wanted and that’s the case here in Lyon.”
Last season, Nkoulou made 38 appearances for Marseille en route to a less-than-satisfactory 13th-place finish in the 2015-16 Ligue 1 season.