Rei Sakuma is a Japanese voice actress, actress, and singer born on January 5, 1965, in Setagaya, Tokyo. Her real name is Reiko Sakuma. She began her entertainment career in 1982 as an idol singer on the NHK program Let's Go Young before transitioning to voice acting in 1985 with her debut role as Pias in the TV anime Dream Star Button Nose. She is currently affiliated with her own agency, Ookina.

Sakuma has built an extensive and diverse career spanning nearly four decades, becoming recognized for her distinctive and playful vocal style. She is particularly well-known in Japan for her long-running role as Batako-san in the beloved children's series Soreike! Anpanman, a character she has voiced since 1988. Internationally, she is perhaps most famous for her role as the energetic Chinese Amazon Shampoo in the classic anime Ranma ½, a part she originated in 1989 and reprised in the 2024 adaptation. Another iconic and widely recognized performance is her role as Jiji, the sassy black cat, in the Studio Ghibli film Kiki's Delivery Service.

Her career is marked by a remarkable range, from cute and heroic characters to cool and complex women. She has voiced the titular sweet rabbit in the long-running Onegai My Melody franchise. In the mecha genre, she has taken on significant roles such as Nina Purpleton in Mobile Suit Gundam 0083: Stardust Memory and Marimeia Barton Khushrenada in Mobile Suit Gundam Wing: Endless Waltz. She also lent her voice to Kazumi "Onee-sama" Amano in the influential OVA Gunbuster. Her filmography includes a vast array of other roles, such as Holly Kujo in JoJo's Bizarre Adventure, Lidvia Lorenzetti in A Certain Magical Index, Aika Sumeragi in Agent AIKa, and Little My in the Moomin series.

Throughout her career, Sakuma has been involved in several recurring collaborations. She was a member of the voice-acting unit DoCo, which performed theme songs for Ranma ½. She has also frequently voiced characters in the works of Studio Ghibli and various Sanrio productions, including My Melody and Cappuccino from the Cinnamoroll franchise. Her talent extends to narration, drama CDs, and dubbing foreign films and animation. With a career that began in the 1980s, Rei Sakuma remains an active and highly respected figure in the Japanese voice acting industry, continuing to take on new roles and reprise her classic characters.