Nobuyo Oyama was a Japanese actress and voice performer best known for originating the definitive voice of the beloved robotic cat Doraemon for over a quarter of a century. Born Nobuyo Yamashita in Tokyo on October 16, 1933, she initially pursued a career in acting, debuting in a 1956 television drama. She entered the world of voice acting in 1957 with a role in the Japanese dub of the American series Lassie. Her unique, raspy voice quickly became her trademark and proved well-suited for voicing young male characters.

Her first major anime role came in 1965 as the title character Punch in Hustle Punch. In the years that followed, she built a diverse portfolio, providing voices for characters such as the first Norakuro in the 1970 series Norakuro, the original Katsuo Isono in the long-running family series Sazae-san, and Jin Kappei in the 1977 mecha series Invincible Super Man Zambot 3.

In 1979, Oyama began her most iconic role, voicing the lead character in the TV Asahi anime adaptation of Doraemon. She would perform the role for 26 consecutive years, becoming so synonymous with the character that creator Fujiko F. Fujio himself praised her portrayal as exactly how Doraemon should sound. Her performance as the gentle, caring, and occasionally frantic robot cat from the 22nd century made her a household name in Japan. She voiced the character in hundreds of television episodes, all the annual theatrical films released during her tenure including Doraemon: Nobita's Dinosaur and 2112: The Birth of Doraemon, and numerous specials such as Doraemon: Come back Doraemon and Doraemon: Nobita's the Night Before a Wedding. Her voice was also used for Doraemon-related merchandise and video games. She stepped down from the role in March 2005 as part of a major cast renewal for the series.

Beyond her work on Doraemon, Oyama had a multifaceted career. She was also a singer, with a record of songs performed as Doraemon selling over a million copies and earning a Golden Disc award. She worked as a television personality, a cooking show expert who published several cookbooks, and even a screenwriter, penning scripts for the detective drama "Shout to the Sun". In 2005, the year she left Doraemon, she was honored with Japan's Broadcasting Woman Award. Later in her career, she took on the villainous role of Monokuma in the popular Danganronpa video game series starting in 2010, a part she played in several games and the anime adaptation.

In 2015, it was publicly disclosed that Oyama was living with dementia, which led to her retirement from voice acting. She passed away on September 29, 2024, at the age of 90. Her legacy as the voice that defined Doraemon for a generation remains profound in Japanese popular culture.