Unlike other capitals, Paris slows down considerably on Christmas Day: the vast majority of shops, bakeries and restaurants close on December 25, including many places that are normally open seven days a week. For a visitor who hasn't planned ahead, the day can fall rather flat if nothing has been arranged in advance. The evening of the 24th, on the other hand, remains a great time to go out: fine-dining restaurants, dinner cruises on the Seine and grand hotels all put on Christmas Eve celebrations, usually requiring booking several weeks ahead.
The illuminated grands boulevards
Boulevard Haussmann and the surrounding streets stay lit up and lively well into the evening of the 24th, even once the department stores have closed, making it a good spot for a stroll before or after a Christmas Eve dinner.
Dinner cruises on the Seine
Several companies offer special Christmas Eve packages on December 24, dinner and entertainment included, with views of the illuminated monuments from the water. Seats sell out fast, so it's best to book as early as November.
The Galeries Lafayette Christmas tree
The store closes its doors on the 25th, but the tree beneath the glass dome remains visible from outside, and the store reopens on the 26th for the winter sales if you're extending your stay.
Tips
On December 25, national museums such as the Louvre or the Musée d'Orsay are closed, but some places do stay open: cinemas, a handful of Asian or neighborhood restaurants, and the grand hotels. Always check specific opening hours before heading out, including for public transport, which often runs on a reduced schedule that day. For a Christmas Eve dinner on the 24th at a well-regarded restaurant, plan to book at least three to four weeks ahead in December, as the best addresses tend to fill up well before the holidays.