Hi there, Margaret!
Welcome back to planDisney! Hydration is very important, especially when navigating a park day at the Disneyland Resort. I’ll be happy to clarify this for you!
According to Disneyland’s park rules,
Guests are allowed to bring outside food and nonalcoholic beverages into the parks as long as they are not in glass containers. Stanley cups aren't specifically listed among the
prohibited items either. As long as your water bottle is made of a non-glass material, you can bring it along for your adventure!
Bonus Tip: As you plan your visit, be sure to keep a note of the
water bottle-filling stations available in each park.
Margaret, I hope this helps and that you have the most wonderful time during your upcoming visit to the Happiest Place on Earth. Stay hydrated out there!
Sending you faith, trust, and pixie dust,
Karmeen