Hi Catherine,
Dinner with the Disney Princesses inside Cinderella Castle at
Cinderella's Royal Table sounds like a perfect way to spend your first evening at Walt Disney World.
I am pleased to tell you that there is no special dress requirement when dining at this restaurant. You will be absolutely fine to dine in casual attire which you would normally wear to the theme parks.
When dining at Cinderella's Royal Table in the past, I would say that approximately half of the young girls present were wearing Disney Princess costumes.
So, to summarise, tiaras and glittering gowns are optional, although young Guests are encouraged to dress up for the occasion.
Wishing you a magical trip filled with memories which will last a lifetime!
Emma