In the mid-1800s, German immigrant butchers in the United States began selling variations of sausages, some of which were thin and long, like the dog breed dachshund. They called these dachshund sausages. Over time, the phrase may have been bastardized into hot dog.

The word frankfurter comes from Frankfurt, Germany, where pork sausages similar to hot dogs originated. These sausages, Frankfurter Würstchen, were known since the 13th century and given to the people on the event of imperial coronations, starting with the coronation of Maximilian II, Holy Roman Emperor, as King.

The name most likely began as a joke about the Germans' small, long, thin dogs. In fact, even Germans called the frankfurter a "little-dog" or "dachshund" sausage, thus linking the word "dog" to their popular concoction.