It is likely that Cheese Fries made many independent debuts starting with the advent of Cheez Whiz in 1953. One early version of Cheese Fries was created by a young fry cook named Austin Ruse at the Dairy Queen on First Capital Drive in St. Charles, Missouri in 1973. They were never placed on the menu but were available for special orders.
In Philadelphia, pizza fries are topped with melted mozzarella and served with pizza sauce on the side, while "Mega Fries" are topped with Cheddar (or sometimes Cheez Whiz) and mozzarella cheese and bacon. Usually served with a side of ranch dressing.
In New York City, Long Island, and New Jersey they are covered with American, Mozzarella, or Swiss cheese, then melted (properly broiled).
In the Southeast, specifically Memphis, TN, cheese fries were created as an employee perk at 'Round the Corner Restaurant in the early 80's. An off-the-menu item created by head chef, Roy Webb for employees on lunch break. Hot, thin fries topped with finely shredded cheddar cheese served with a side of homemade ranch dressing.
In other parts of the US, nacho cheese is often used, especially in snack-stand type settings.
In Ireland a popular variation called "Taco Fries" consists of fresh cut chips covered in sub sauce and shredded Cheddar. Piled on top of the cheese are ground beef, tomato, peppers, onions, and various seasoning.
In Bulgaria, a common side dish offered in most restaurants consists of French fries, topped with grated or crumbled sirene.
Fast food chain In-N-Out Burger serves "Animal Style Fries" which are covered in melted cheese, grilled onions, and Thousand Island dressing.
Some German "Imbisse" (fast food joints) serve a variation on chilli cheese fries with bolognese sauce instead of chilli.
In the Netherlands a dish named 'kapsalon' is served as fast food. This consist of fries covered with cheese, salad and shawarma or doner kebab. It is often consumed with large amounts of garlic sauce and/or chili sauce.
The United Kingdom chips and cheese are often served in pubs as a popular type of 'pub grub'. Preparation includes the pouring of cheddar sauce over chips or sprinkling cheddar over chips and then putting the dish under a grill.