Hajime Mizoguchi (溝口 肇, Mizoguchi Hajime, born April 23, 1960 in Tokyo) is a Japanese cellist and composer.
Mizoguchi started playing piano at the age of 3, and the cello at the age of 11. From 1978–1985 he attended the Tokyo National University of Fine Arts and Music where he majored in violoncello.
In 1986, he released his first album, Half Inch Dessert, being listed as composer, arranger, and performer. From that time on, he has released more than 20 albums including motion picture soundtracks.
His compositions include the soundtrack to the animated feature film Jin-Roh: The Wolf Brigade. In 2006, he composed the music to Tokimeki Memorial Only Love (along with Teruyuki Nobuchika) and the Fuji TV noitamina series Jyu Oh Sei. He composed and plays the opening and ending theme for TV Asahi's series See the World by Train, which has run since June 1987. His song "Bruce", from 1986's Oasis Behind the Clear Water, appears in various scenes of the 1987 animation To-y.