Yō Inoue was a Japanese voice actress born in Tokyo on December 4, 1946. She graduated from Tokyo Metropolitan Yashio High School and Waseda University. Her career in the entertainment industry began with her involvement in the theatre, after which she started working on the TBS morning program Young 720. Over the course of her career, she was affiliated with several agencies, including Production Baobab and, later in her life, Tokyo Haikyō Cooperative Association. Beyond voice acting, Inoue also worked as a radio writer, a dancer, and a fortune-teller. She passed away on February 28, 2003, at the age of 56 due to pulmonary edema.

Inoue is best known for her iconic roles in numerous anime series and films from the late 1970s through the 1990s. In the Gundam franchise, she provided the voice for the character Sayla Mass, Haro, and Kikka Kitamoto across the original Mobile Suit Gundam television series, the movie trilogy, and later entries like Gundam Evolve and Mobile Suit SD Gundam's Counterattack. Her other famous roles include Kanuka Clancy in the Patlabor franchise, Ran in the Urusei Yatsura series and its films, and Osomatsu Matsuno in the Osomatsu-kun series. She also voiced Ryou Bakura in the Yu-Gi-Oh! television series. Her filmography includes a wide range of other notable characters such as Reika Sanjo in Muteki Kōjin Daitarn 3, Cairo in Tōshō Daimos, Manabu Karui in Future Robot Daltanious, Peachy in Gordian the Warrior, Kuroma in Kappa no Sanpei, Jyako Amano in High School! Kimengumi, Ippei Yagyū in Ninjaman Ippei, Ivano in Macross 7 and its film Macross 7 the Movie: The Galaxy's Calling Me!, Sophine in BAOH, the Chairwoman in Demon Hunter Makaryūdo, Pimer in Gatchaman II, Nyago in Koguma no Misha, Hiroshi Taikai in Gold Lightan - The Golden Warrior, Queen Zurline in Shōnen Santa no Daibōken, Misty Sheila in Plawres Sanshirō, Panni in Fatal Fury: The Motion Picture, Yuzuha in Tenchi The Movie 2 - The Daughter of Darkness, Momiji Principal in Lil' Red Riding Hood Cha-Cha, Neris in The Legend of Lyon: Flare, the Snack Roman Mama in Domain of Murder, and the role of Pimer in Gatchaman II.

Throughout her career, Yō Inoue had many recurring collaborations with specific franchises and production staff. Her most significant long-term collaboration was with the Gundam series, where she reprised her role as Sayla Mass and Haro on multiple occasions over more than two decades. She similarly worked across several installments of the Patlabor and Urusei Yatsura franchises. Following her death, her role as Ryou Bakura was succeeded by Matsumoto Rika, while her performance as Sayla Mass in later works like Mobile Suit Gundam: The Origin was succeeded by Megumi Han. A notable achievement in her career is the enduring legacy of her performances, particularly her dual roles as the human pilot Sayla Mass and the robotic pet Haro in the original Mobile Suit Gundam, which have become foundational to one of the most famous anime franchises in history. Her final recorded performance as Sayla Mass was posthumously featured in Mobile Suit Zeta Gundam: A New Translation - Love is the Pulse of the Stars, released in 2006, using her original dialogue from earlier recordings.