Keiko Yamamoto was a Japanese voice actress from Osaka Prefecture, born on August 7, 1940. She passed away on April 18, 2024, at the age of 83. Yamamoto made her voice acting debut in 1963 and became a founding member of the talent agency Aoni Production in 1969. Throughout her extensive career, she was known for voicing a wide range of characters, including young boys, tomboyish girls, and older women.

Her breakthrough role came in 1965 when she voiced the title character in Tatakae! Osper. She went on to play many iconic and long-running roles. She voiced the character Bakabon in the Tensai Bakabon series and its predecessor, Ganso Tensai Bakabon. In the long-running series Sazae-san, she began voicing Hanako Hanazawa in 1972, a role she continued for over 50 years. She was also well-known as the voice of Shouta Yamada in Chibi Maruko-chan and as Sunakake Babaa across multiple iterations of the GeGeGe no Kitarō series, including films like Gegege no Kitarō: Nippon Bakuretsu!!, Gegege no Kitarō: Yōkai Tokkyū! Maboroshi no Kisha, Gegege no Kitarō: Obake Nighter, and Gegege no Kitarō: Daikaijū.

Yamamoto's filmography includes a vast number of other roles across anime, films, video games, and tokusatsu. In anime, her roles included Choromatsu and Karamatsu in Osomatsu-kun, Eros in Ochamegami Monogatari Korokoro Poron, Kaoru Yanagizawa in Attack No. 1, Akadō Suzunosuke Konno in Akado Suzunosuke, Ms. Ōishi in Chibi Maruko-chan and its film Eiga Chibi Maruko-chan: Italia kara Kita Shōnen, Chikako in Himitsu no Akko-chan and its film Himitsu no Akko-chan: Umi da! Obake da!! Natsu Matsuri, First Little Pig in World Fairy Tale Series, Nachiguron in Kinnikuman: Kessen! Shichinin no Seigi Chōjin vs. Uchū Nobushi, Tubby and Tubby Tompkins in Little Lulu, Matsuko Yamada in Nono-chan, and Gabo-chan in Ultraman Company Kochira Ulkan Tokusō-tai de-su!. She also had roles in Dr. Slump & Arale-chan films, Soreike! Anpanman films, and voiced Tenshi Dan-Jack and Jintei Dan-Jack in the Bikkuriman series and its films. Her work extended to tokusatsu, where she provided the voice for Robocon in Ganbare!! Robocon, and for characters in Chōriki Sentai Ohranger and its film. In video games, she was the voice of Chicken Little in the Japanese dub of the Disney film and its Kingdom Hearts II appearance, as well as roles in games like Dark Chronicle and Popful Mail. Her other anime roles included Junko Asami in Judge, Koume Jinguji in Baby Baachan, Ton in Manga Aesop Monogatari, Takeo Yamakawa in Two Down Full Base, and Kayukayubouya in Soreike! Anpanman: Gomira no Hoshi.

In late 2023, Yamamoto retired from her long-running roles in both Sazae-san and Chibi Maruko-chan, marking the end of roles that had spanned 30 and 50 years, respectively. She passed away in April 2024 due to sepsis.