is a French actor. He made his acting debut in the two-part television miniseries La dame d'Izieu in 2007, followed by films such as LOL (Laughing Out Loud) (2008), The Army of Crime (2009), Romantics Anonymous (2010) and Just Like Brothers (2012). In 2014, Niney starred as fashion designer Yves Saint Laurent in the biopic of the same name, for which he won a César Award for Best Actor.

Niney was born in Boulogne-Billancourt, Hauts-de-Seine, France. His family is of Sephardic Jewish (Egyptian-Jewish) and Catholic background. His father, François Niney, is a film professor at Normale Sup, La Fémis and Sciences Po. His mother was born in Belgium and is an author of creative leisure manuals

In 2007, Niney studied at the French drama school Cours Florent.

Niney made his acting debut in the two-part television miniseries La dame d'Izieu in 2007, followed by films such as LOL (Laughing Out Loud), The Army of Crime, Romantics Anonymous and Comme des frères.

In October 2010, at age 21, he became the youngest member of the Comédie-Française.

In 2014, Niney starred as fashion designer Yves Saint Laurent in the biopic of the same name directed by Jalil Lespert, for which he won a César Award for Best Actor.

In February 2023, it was announced that Niney will star in a 7-episode comedy series that he co-created and co-wrote with Igor Gotesman for Netflix titled Fiasco.