Last name הילריוס (Hilarius 
, הילריוס 
) , across the world, is a rare family name. The cognomen הילריוס is characteristic of Netherlands, where it is a rare surname, Malaysia, and Germany. Not in comparison with a country's population, it is the most numerous in Indonesia, Netherlands, and Germany. More frequently, הילריוס is the forename as well as the last name.