The 21-year-old forward will now remain at the French Ligue 1 side until 2019.
He told Lyon’s website: “I’m happy. Now we have to continue working. I want to score, to play and I hope we can qualify for Europe next season.
“I’m proud of myself. I want to also thank everyone who helped me get this far. This extension shows that the team has confidence in me.”
Although he has yet to score for Lyon this season, N’Jie has made a superb start to his international career with the Indomitable Lions.
He scored on his debut on 6 September in a 2-0 win away to Democratic Republic of Congo and four days later he grabbed a brace to helpCameroon beat Ivory Coast 4-1.