Nobuyo Ōyama (大山 のぶ代, Ōyama Nobuyo), born Nobuyo Yamashita (山下 羨代, Yamashita Nobuyo, October 16, 1933, in Shibuya, Tokyo), is a former Japanese actress, voice actress and singer affiliated with Actors Seven. She is best known for playing the title character in the long-running Doraemon anime series. She is also well known as the voice of Monokuma, the main villain from the Danganronpa video-game series. She played him in both the video games and in the anime series Danganronpa: The Animation.
It was reported on May 13, 2015, that Ōyama was living with dementia, putting any future work on hold. This notably prevented her from reprising her role as Monokuma in any further episodes of the anime series Danganronpa 3: The End of Hope's Peak High School. Her ongoing roles were taken over by Wasabi Mizuta (Doraemon) and Tarako (Monokuma).