Cognomen Кеплер (Kepler 
, Keppler 
, Кеплер 
) , in the world, is a common surname. The surname Кеплер is habitual in Germany, where it is quite a rare surname, Estonia, and the United States. In absolute terms, it is commonest in Germany, the United States, and Brazil. Very seldom, Кеплер is the forename as well as the last name.