Family name Backer-Groendahl (Backer-Groendahl 
) , all around the world, is a very rare cognomen. The surname Backer-Groendahl is habitual in Northern Europe, particularly Norway, where it is quite a rare surname, and Denmark, where it is a very rare surname. Much less frequently, Backer-Groendahl is the forename as well as the last name. Parts of the name also exists independently as a last name Backer, and a last name Groendahl.