Yes, you are absolutely allowed to bring containers into Walt Disney World, including coolers, backpacks, and water bottles, but they must adhere to specific safety and size guidelines. Coolers and bags cannot exceed 24 inches long x 15 inches wide x 18 inches high. Crucially, glass containers are strictly prohibited, with the only exception being small baby food jars or essential medication containers. Another vital rule is the "no loose ice" policy; if you are bringing a cooler to keep drinks or snacks cold, you must use reusable ice packs or dry ice, as loose ice cubes are not permitted through security. Many visitors bring refillable plastic or stainless steel water bottles to take advantage of the free water stations located throughout the parks. Additionally, while you can bring your own food and non-alcoholic beverages in these containers, you are not permitted to bring outside alcohol or any items that require heating (like a microwaveable meal). These rules ensure that security checkpoints move efficiently and that the park remains safe for the thousands of families navigating the walkways and attractions each day.