Surname Mikaja (Микая 
, Mikaja 
) , around the world, is a rare last name. The family name Mikaja is habitual in Estonia, where it is a rare surname, Russia, and Ukraine, where it is an extremely rare surname. Not in comparison with a country's population, it is the most numerous in Russia, Estonia, and India. Very seldom, Mikaja is the forename as well as the last name.