The only Greek restaurants I can find in Orlando are near Downtown, not exactly close to Disney...
The Greek Corner Restaurant (407) 228-3030 1600 N Orange Ave, Orlando, FL
Cafe Annie (407) 420-4041 131 N Orange Ave, Orlando, FL
Eva's Tiramisu Cafe (407) 228-0303 1600 N Orange Ave, Orlando, FL
Cedar's Restaurant is supposed to be a great middle-eastern restaurant, but I havent tried it. It's phone and address are: 407-351-6000 7732 W Sand Lake Rd Orlando, FL 32819