Mami Koyama (小山 茉美, Koyama Mami?, born January 17, 1955), credited as 小山 まみ until 1980, is a Japanese voice actress and J-pop vocalist who was born in Nishio, Aichi. Koyama is affiliated with Aoni Production.
Her best-known voice roles include Arale in Dr. Slump, Minky Momo in Mahou no Princess Minky Momo, Launch in Dragon Ball, and Ryoko Mendou in Urusei Yatsura.