Cognomen ארהרדט (Erhardt 
, Ehrhardt , ארהרדט 
) , all over the world, is a common surname. The surname ארהרדט is characteristic of Marshall Islands, where it is a common surname, Germany, where it is quite a common surname, and Austria, where it is quite a rare surname. Not in comparison with a country's population, it is the most numerous in Germany, the United States, and France. Very seldom, ארהרדט is the forename as well as the last name.