Cognomen もりやま (Moriyama 
, もりやま) , all around the world, is quite a rare family name. The family name もりやま is habitual in Hong Kong, where it is a rare surname, Japan, and Portugal. Measured by absolute frequency, the name is most common in Brazil, Japan, and the United States. Much less frequently, もりやま is the forename as well as the last name.