Yes, Walt Disney World and Disneyland Resort both allow guests to bring in Hydroflasks and other insulated stainless steel water bottles as of 2026. This is a highly recommended practice for managing the intense Florida or California heat while avoiding the high cost of bottled water inside the parks, which can exceed $5.50 per bottle. The primary restrictions are that the container must not be made of glass and it cannot contain alcoholic beverages. Your Hydroflask does not need to be empty when you enter; you can bring it filled with water or ice, though it will be subject to a security inspection at the park entrance. To stay hydrated throughout the day, Disney provides multiple water bottle refill stations, and any Quick-Service dining location will provide a complimentary cup of ice water upon request, which you can use to top off your flask.