Sayuri Sadaoka is a Japanese voice actress born on September 4, 1955, in Kanagawa Prefecture, Japan. She is a graduate of Tamagawa University, where she majored in theater within the Department of Performing Arts. Her career in the performing arts began in 1979 with the Dōra Theater Company, and she subsequently became affiliated with several voice acting agencies, including 81 Produce and Mausu Promotion, before joining Production Ace.

Sadaoka is widely recognized for her warm and distinguished vocal quality, which has made her a sought-after talent for roles portraying grandmothers, mothers, and other mature female characters. Her extensive filmography includes a multitude of such roles across a wide range of anime series and films. Notable examples include voicing Kukuru's Grandmother in The aquatope on white sand, Shaomin's Grandmother in Flavors of Youth, Lizbeth Sergeant in The Ancient Magus' Bride, Sanae Akanegi in Diamond Daydreams, and Natsuko's Mother in Kurage no Shokudō. She also provided voices for characters such as Madam 44 in Yurei Deco, Mrs. Shimazu the landlady in JAPAN, Our Homeland, and Anna in the Fastening Days series. Her work extends to OVA productions as well, including roles such as Bluebeard's mother and a video rental clerk in the Yonimo Osoroshii Grimm Dōwa series, and the character Anko in both Ultra Nyan: Hoshizora Kara Maiorita Fushigi Neko and Ultra Nyan 2: Happy Daisakusen.

While she is particularly associated with maternal and elderly roles, Sadaoka's career demonstrates notable versatility. She has voiced principal characters such as Sirius Warzak in The Brave of Gold Goldran and has been a recurring presence in long-running and iconic franchises like Crayon Shin-chan, Detective Conan, Sazae-san, Doraemon, and Anpanman. Her voice work is not limited to anime; she has also contributed to popular video games, including Dragon Quest XI and Final Fantasy VII Rebirth, and has dubbed voices for foreign films and animations such as Paddington and Inside Out.

Throughout her decades-long career, which began in 1979, Sayuri Sadaoka has built a reputation for professionalism, versatility, and a unique ability to bring warmth and heart to her characters, even in smaller supporting roles. Her contributions to the industry are marked by a consistent presence and a respected body of work that spans animation, film, and video games.