A corn dog is a hot dog encased in a cornmeal batter and fried or baked. The corn dog is intimately associated with fairs, especially in the United States, and it also pops up in school cafeterias as well. Depending on how it is prepared, a corn dog can be high in fat or relatively healthy, and it is usually dressed with a condiment such as mustard. Many grocery stores carry corn dogs, usually frozen, and they can be reheated through baking, microwaving, or frying.

The origins of the corn dog are disputed. The food appears to have emerged at some point in the 1940s, but several different people lay claim to the invention of the corn dog. The 1942 Texas state fair appears to have been the venue in which the corn dog was popularized, but evidence suggests that corn dogs were being made and served around the United States before this point. Whoever the original inventor was, the corn dog came to be a big success.

Early corn dogs were made by rolling a frankfurter in a thick cornmeal batter which puffed up and became bready when cooked. In the late 1940s, the stick was added to corn dogs to make them easier to eat, and most modern corn dogs are mounted on a stick. Consumers squeeze condiments along the length of the corn dog, which may come wrapped in wax paper for tidiness, and eat it like a Popsicle.

Since corn dogs can be eaten one handed with minimal fuss, they are a popular choice at fairs and carnivals. Frankfurters in general frequently pop up in this venue, since they are cheap and relatively easy to cook, making them an easy choice for food vendors. Since the corn dog is associated with the fair environment in the minds of some people, they are sometimes considered to be special or unique treats, and they are not often made at home.

When made with high quality sausage and a good batter, a corn dog can approach the level of the gourmet. Most, however, are made with cheap materials which are heavily salted and often loaded with fats as well. Especially when fried, a corn dog may not represent the most ideal nutritional choice, with the baked corn dog being the most healthy option. Choice of condiments can also have an impact on the nutritional value of the corn dog. Although mustard is the most common, relish, sauerkraut, pickles, ketchup, and mayonnaise are also used, depending on region and personal taste.