Family name Рајко (Rajko 
, Raiko 
, Рајко ) , around the globe, is quite a rare last name. The last name Рајко is habitual in Southern Europe, particularly Slovenia, where it is quite a common surname, Montenegro, and Croatia, where it is quite a rare surname. In absolute terms, it is the most numerous in Slovenia, Japan, and Croatia. More prevalently, Рајко is the forename as well as the last name.