Meiko Haigō is a Japanese singer-songwriter and voice actress from Tokyo, born on May 6, 1978. Her career began in music, initially gaining attention as a member of the vocal unit Fragrance Balance, which won a special jury award at a Yamaha-sponsored music contest in 1996. This led to a contract with Yamaha Music Communications, and she debuted as a solo artist in 2001 with the single Tomato Soup. Her musical work includes composing for a 2005 music video, Dore Dore no Uta, which was animated by Studio Ghibli. Since 2006, she has operated under her own independent label, nanno record, and continues to perform live across Japan.

Haigō is most widely recognized as the voice provider for the VOCALOID software MEIKO, a singing synthesizer application developed by Crypton Future Media. Released in 2004, MEIKO was the first Japanese VOCALOID, and the character was named after Haigō. Her vocals form the basis of the character's singing voice, which is noted for its mature and steady quality. This role has remained a central part of her public identity, and she has participated in events celebrating the software's anniversary, such as the MEIKO 15th Year Anniversary event in 2019.

While her career is deeply rooted in music, Haigō has also taken on voice acting roles that directly connect to the MEIKO character. She voices the character MEIKO in anime adaptations of the Project SEKAI franchise, a mobile rhythm game featuring VOCALOID characters. Her credits include the 2023 television mini-series Project Sekai: Journey to Bloom and the upcoming 2025 film Colorful Stage! The Movie: A Miku Who Can't Sing.

Haigō has ongoing professional relationships with the voice providers for other Crypton VOCALOID characters. She has frequently collaborated with Naoto Fuuga, the voice of KAITO, and Yuu Asakawa, the voice of Megurine Luka. These collaborations include joint appearances at anniversary events and the release of collaborative music singles, such as Kyoumeikairo and Happy Hour in 2022.