Yes, you can absolutely take a CamelBak or any hydration bladder into Disneyland in 2026. It is highly encouraged as a way to stay hydrated in the California sun. However, there are two important rules: first, the backpack itself must not exceed the standard bag dimensions of 24" long x 15" wide x 18" high. Second, the bladder must be completely empty when you go through the security checkpoint. Security needs to ensure you aren't bringing in alcohol or glass containers. Once inside the park, you can fill your CamelBak for free at the various "Hydration Stations" located throughout Disneyland and California Adventure (such as the one in Galaxy's Edge or near the Frontierland restrooms). This is a much better alternative to buying $5 bottled water and is a favorite "pro-tip" for 2026 travelers looking to save money and reduce plastic waste.