Saeko Ooki is a Japanese voice actress born on November 24 in Chiba Prefecture. She is affiliated with the talent agency Office Osawa. Her career in voice acting began to take shape in the 2020s, and she has since built a portfolio of roles across anime television series, animated films, and video games.

One of Ooki's notable roles is Rin Hirama in the 2024 anime adaptation of Inio Asano's manga, Dead Dead Demon's Dededede Destruction. She voiced the character in both the two-part compilation film and the subsequent television series. Her performance as Rin Hirama, a high school girl and childhood friend of another character, is part of an ensemble cast in this science fiction story.

Her work in anime includes a range of supporting and guest characters in various series. Her credits from 2024 include appearances in Re: From Zero Starting Life in Another World, The Elusive Samurai, and 2.5 Dimensional Seduction. She has also been cast in series such as Tying the Knot with an Amagami Sister, A Terrified Teacher at Ghoul School!, and the fantasy anime I May Be a Guild Receptionist, But I’ll Solo Any Boss to Clock Out on Time. Her work extends into 2025 with roles in series including Honey Lemon Soda, The Brilliant Healer's New Life in the Shadows, and the anime adaptation of the game Summer Pockets.

In addition to anime, Ooki is active in the video game industry. She voices characters in major mobile and online games, including Izumi Oishi in The Idolmaster Cinderella Girls Starlight Stage and Atago and Duisburg in Azur Lane. She has also contributed her voice to games like Monster Strike and Touhou LostWord, where she voices Koishi Komeiji. Her performances occasionally extend to character songs, particularly within The Idolmaster franchise, showcasing her range as a performer.