Yoko Soumi is a Japanese actress and voice actress born on May 31, 1962, in Niigata Prefecture. She is affiliated with Kakehi Production and is also a member of the theater company Aun Company. She was previously associated with Mausu Promotion. Her career in voice acting began in the late 1980s, and she has been active in the industry for over three decades.

Soumi has built a substantial filmography, lending her voice to a wide array of characters across anime series, OVAs, video games, and dubbed foreign productions. One of her most acclaimed roles is Olivier Mira Armstrong in Fullmetal Alchemist: Brotherhood, a character known for her strength and commanding presence. She also voiced the strict and capable commander Kusunoki in the 2022 series Lycoris Recoil. In the 2021 reboot of Shaman King, she reprised the role of Lyserg Diethel, a character she originally voiced in the 2001 adaptation, showcasing her long-standing connection to certain franchises. Her other significant anime roles include Atsuko Urameshi in Yu Yu Hakusho, Elizard in A Certain Magical Index III, Botan Saotome in 7SEEDS, Yukie Kariya in Fafner, Kei in the Pretty Rhythm series, and Madame Marciano in Coyote Ragtime Show. She has also appeared in long-running franchises such as Pokémon and Case Closed.

Beyond anime, Soumi is highly active in voice dubbing for live-action films and TV series. She is the regular Japanese voice for actresses such as Cameron Diaz and Sandra Oh. Her extensive dubbing work includes voicing Natalie Cook in the Charlie's Angels films for Diaz, Cristina Yang in Grey's Anatomy for Oh, and roles in major films like Gladiator (as Lucilla), the Jason Bourne series (as Nicky Parsons), and Star Trek: Voyager (as Seven of Nine).

In addition to her on-screen voice work, Soumi has contributed to video games, with notable roles such as Ayame in the Tenchu series, Judge Drace in Final Fantasy XII, and Tokiko Shigure in AI: The Somnium Files – Nirvana Initiative. Her performance as Zorin Blitz in the Hellsing Ultimate OVA series is also well-regarded. Her career demonstrates a consistent ability to portray strong, mature women, from military leaders and law enforcement officers to complex heroines.