Kodaira is a city located in the western portion of Tokyo Prefecture, Japan. As of 1 April 2021, the city had an estimated population of 195,207 in 93,654 households, and a population density of 9500 persons per km2. The total area of the city was 20.51 square kilometres (7.92 sq mi).

The Seibu Kokubunji Line is a railway line in Tokyo, Japan, operated by the private railway operator Seibu Railway.