Cognomen Гиллен (Gillen 
, Гиллен 
) , across the world, is a common surname. The cognomen Гиллен is habitual in Luxembourg, where it is quite a common surname, Ireland, and Gambia. Measured by absolute frequency, it is the most numerous in the United States, the United Kingdom, and Ireland. Very seldom, Гиллен is the forename as well as the last name.