You might have an idea that seems just perfect for the Walt Disney Company, but Disney doesn't necessarily want to know about it. As a general policy, Disney rejects most—if not all—unsolicited ideas, in large part to protect the company from legal claims. Sometimes, the company is already working on an idea someone else is trying to submit. There are ways to get your ideas in front of top decision makers in the House of Mouse, but it's not easy.
Make sure you have a great idea and perfect pitch. Try it on friends who you can trust to be critical, especially friends who are in the same business. Study the field, know your competitors and be prepared to differentiate your idea from what's already out there. This will help you whether you end up dealing with Disney or another company.
Get an agent. Ideally, find an agent who deals with Disney regularly or deals with a Disney subcontractor who may have use for your idea. Disney will not accept unsolicited ideas from someone with no representation. In fact, Disney's policy is to reject all unrepresented, unsolicited ideas.
Wait. The odds of success are low, and these things can take a very long time. While it's acceptable to call your agent for occasional updates, you also have to understand your agent will call you if he or she has some (hopefully good) news to report. Remember, your agent is working for you and is probably on commission—so it's in his or her interest to give your idea the best possible effort.
If you're still convinced your idea is great, try re-targeting it for a different company. You may think you have the perfect idea for Disney, but there are dozens of other companies that may be more receptive. If you establish a reputation in your field, then over time you may be in a better position to approach Disney with a later idea. If you get big enough, Disney may even come to you.