A hot dog is a dish consisting of a grilled, steamed, or boiled sausage served in the slit of a partially sliced bun. The term hot dog can refer to the sausage itself. The sausage used is a wiener or a frankfurter. The names of these sausages commonly refer to their assembled dish. Hot dog preparation and condiments vary worldwide. Typical condiments include mustard, ketchup, relish, onions in tomato sauce, and cheese sauce. Other toppings include sauerkraut, diced onions, jalapeños, chili, grated cheese, coleslaw, bacon and olives. Hot dog variants include the corn dog and pigs in a blanket. The hot dog's cultural traditions include the Nathan's Hot Dog Eating Contest and the Oscar Mayer Wienermobile.

A sausage is a type of meat product usually made from ground meat—often pork, beef, or poultry—along with salt, spices and other flavourings. Other ingredients, such as grains or breadcrumbs, may be included as fillers or extenders.