Réveillon is the traditional New Year's Eve feast in France and other French-speaking regions.
The word réveillon comes from réveil, meaning “waking,” and originally referred to a late-night meal that kept people awake after religious observances. It is used for both the Christmas Eve and New Year's Eve feasts, so context matters. A New Year's Réveillon may include several courses, champagne, seafood, oysters, foie gras or other regional specialties.
A Réveillon is not a single fixed menu and should not be confused with the galette des rois, a pastry traditionally associated with Epiphany in January. Modern celebrations vary widely: some people eat at home, while others attend restaurant dinners or parties. The term describes the late festive meal and, by extension, the surrounding celebration rather than one particular dish.