Yes, you are absolutely allowed to wear a CamelBak or any hydration bladder at Disney Parks. In fact, it is highly recommended as a "pro-tip" for surviving the intense Florida or California heat. You can fill it with water at any of the parks' water bottle filling stations or at "Quick Service" food locations, where you can ask for free cups of ice water. However, there are a few "security" rules to keep in mind. First, when you go through the security scanner, you may be asked to open the main compartment so the officers can see the bladder. Second, while you can bring a CamelBak, you cannot bring dry ice or loose ice in it (it must be in a reusable ice pack or the water must be liquid). Third, the CamelBak counts as your "bag," so if it is exceptionally large or has many pockets, it might slow you down at the entry point. In 2026, many frequent guests use smaller, sleek hydration packs that fit comfortably even while sitting in ride vehicles like Guardians of the Galaxy: Cosmic Rewind or Avatar Flight of Passage, though you should always secure the straps to prevent them from getting snagged.