Sayumi Watabe is a Japanese voice actress from Hokkaido, born on September 25. She is affiliated with the talent agency Sigma Seven, having initially joined its e division before being promoted to the main branch in November 2021. Her career began after she passed the third Sigma Seven audition in 2009, and she officially debuted in 2010. In the early years of her career, she focused primarily on narration work for variety and documentary programs.

Her first regular role in an anime television series was as Mori Shiki in Minami Kamakura High School Girls Cycling Club in 2017. A significant turning point in her career came in 2018 when she landed her first starring role as Akira Tachibana in the romantic drama After the Rain. This performance helped establish her as a versatile voice actress capable of leading roles.

Watabe has built a diverse filmography across anime, original net animations (ONA), and video games. In anime television, she is known for several prominent roles. She voices Eleonore Bianca in The Misfit of Demon King Academy and its second season. She plays Sakura Banka in both BUILD-DIVIDE -#000000- CODE BLACK and its sequel BUILD-DIVIDE -#FFFFFF- CODE WHITE. Her other television roles include Marimo Jingūji in Muv-Luv Alternative, Freezing Astaroth in Combatants Will Be Dispatched!, Madoka Maka in Wixoss Diva(A)Live, and Chiyo Fujii in Major 2nd. She also voiced Kato in A Certain Scientific Accelerator and Els in BEASTARS. In 2024, she was cast as Aria Kisaki in 2.5 Dimensional Seduction and as Lotus Rika Ren in the Workshop Battle arc of Tower of God.

Her work also extends to original net animations and video games. In 2022, she voiced Kagaho Sasahara in the ONA Spriggan. In the realm of video games, she is recognized as the voice of Birmingham in Azur Lane, Asagi Igawa in Action Taimanin, and Fiona in Gran Saga.