Cognomen Йонкер (Jonker 
, Йонкер 
) , all around the world, is a common surname. The last name Йонкер is characteristic of Netherlands, where it is quite a common surname, South Africa, and Malta, where it is quite a rare surname. Not in comparison with a country's population, it is commonest in Netherlands, South Africa, and the United States. Very seldom, Йонкер is the forename as well as the last name.