Cognomen Janjus (Janjus 
) , all around the world, is a rare family name. The last name Janjus is characteristic of Bosnia and Herzegovina, where it is quite a rare surname, Serbia, and Canada, where it is an extremely rare surname. Measured by absolute frequency, this name is the most popular in Bosnia and Herzegovina, Serbia, and the United States. Much less frequently, Janjus is the forename as well as the last name.