Hi Lauren:
Dining at Walt disney World is a fairly casual experience, so in general, a decent tee-shirt and pair of shorts will suffice.
For Disney's fancier
Signature Dining Experiences, the "Dress Code Guidelines" state the following:
Men: Khakis, slacks, jeans, dress shorts, collared shirts. Sport coats are optional.
Ladies: Capris, skirts, dresses, jeans, dress shorts.
Not permitted in dining room: Tank tops, swimwear, hats for gentleman, cut offs, or torn clothing. While T-shirts are now allowed, the policy remains that T-shirts with offensive language or graphics are not acceptable.
One exception is Disney World's delicious and award-winning dining experience at
Victoria & Albert's. The following "Proper Dining Attire" is required at Victoria & Albert's:
Men: Dinner jackets with dress pants/slacks and shoes. Ties are optional. (Please no jeans, shorts, sandals, flip-flops or tennis shoes.)
Ladies: Cocktail dress, dressy pant suit, skirt/blouse or nice dress.(Please no jeans, shorts, capri pants, sandals, flip-flops or tennis shoes.)
Happy dining and enjoy your vacation.