Kokubunji (国分寺市 Kokubunji-shi) is a city located in Tokyo Metropolis, Japan. The city was founded on November 3, 1964.
As of June 1, 2008, the city has an estimated population of 117,335, with 55,459 households and a population density of 10,057 persons per km². The total area is 11.48 km².
Kokubunji is the home of the Hitachi Central Research Laboratory, which contains one of the largest natural preserves in the area surrounding Tokyo.
Tatsunoko has its headquarters in Kokubunji.
Kokubunji operates ten public elementary and five junior high schools.
Kokubunji High School is operated by the Tokyo Metropolitan Government Board of Education.