Yes, you are encouraged to bring your own water bottles into Disney parks, and it is one of the best ways to save money during your visit. Disney allows outside non-alcoholic beverages as long as they are not in glass containers. You can bring plastic bottles, aluminum flasks (like HydroFlasks), or even reusable pouches. This applies to both Disneyland in California and Walt Disney World in Florida. A pro-tip for 2026: there are numerous contactless water bottle refill stations located near restrooms and in newer lands like Star Wars: Galaxy's Edge. If you run out of your own water and don't want to use a fountain, you can go to any Quick Service dining location and ask for a "Cup of Ice Water," which they are required to provide for free, rather than paying $5+ for a bottled Dasani.