In the American Disney theme parks, adults wearing a costume is strictly prohibited. According to the Disney resorts’ dress code, costumes or masks may not be worn by guests who are 14 years of age or older. Refusal to comply with this dress code can result in a guest being refused admittance to the park or even getting kicked out. Why? Well, some people’s costumes are too good and they can be confused for the actual princesses and princes walking around Disney theme parks. The only time you can dress up at Walt Disney World or Disneyland is during the seasonal Halloween parties.