Patty melt is an American sandwich consisting of Swiss cheese and an onion-topped hamburger patty between slices of grilled rye bread. The flavorful sandwich was invented in California in the late 1940s by Tiny Naylor, the owner of Biff's and Tiny Naylor restaurants.

It is believed that the dish served as an inspiration for the famous tuna melt, using tuna as a substitute for the hamburger patty. Most often, patty melt is served with French fries, lettuce, pickles, tomatoes, and a Thousand Island dressing on the side.