Surname Оояма (大山 
, Oyama 
, Ooyama 
) , all around the world, is a common last name. The cognomen Оояма is characteristic of Sub-Saharan Africa, particularly Gabon, where it is quite a rare surname, Nigeria, and Cameroon. Measured by absolute frequency, it is the most numerous in Nigeria, China, and Brazil. Likewise, Оояма is the forename as well as the last name.