What is the French New Year's Eve feast or celebration called?

The French New Year’s Eve feast or celebration is called Réveillon de la Saint-Sylvestre.

Réveillon refers to a late-night festive meal, and Saint-Sylvestre is the French name associated with December 31. The occasion may be celebrated at home, in a restaurant, or at a larger organized gathering. Menus often emphasize special foods and drinks, reflecting the idea of marking the change of year with an unusually elaborate meal.

The expression is specific to the New Year’s Eve celebration and should not be confused with Réveillon de Noël, the comparable late-night Christmas Eve meal. France does not have one single nationwide midnight ritual equivalent to Spain’s twelve grapes. Customs vary by household and region, while public celebrations may include fireworks, concerts, or gatherings at major city landmarks.