A cheeseburger is a hamburger with a slice of melted cheese on top of the meat patty, added near the end of the cooking time. Cheeseburgers can include variations in structure, ingredients and composition. As with other hamburgers, a cheeseburger may include various condiments and other toppings such as lettuce, tomato, onion, pickles, bacon, avocado, mushrooms, mayonnaise, ketchup, and mustard.

A hamburger, also called a burger, is a food consisting of fillings—usually a patty of ground meat, typically beef—placed inside a sliced bun or bread roll. The patties are often served with cheese, lettuce, tomato, onion, pickles, bacon or chilis with condiments such as ketchup, mustard, mayonnaise, relish or a "special sauce", often a variation of Thousand Island dressing and are frequently placed on sesame seed buns. A hamburger patty topped with cheese is called a cheeseburger.