Yes, the San Diego Zoo is open on Christmas day! It's a popular place for families to visit during the holiday season. The zoo has many different animal exhibits, including lions, tigers, pandas, and even a petting zoo. You can also enjoy special activities and events like the Santa Paws Photo Experience, where you can get a picture with Santa and your favorite animal. The zoo is also decorated with festive lights and decorations for the holidays, making it a truly magical experience.