The American School in Japan is an international private day school located in the city of Chōfu, Tokyo, Japan. The school consists of an elementary school, a middle school, and a high school, all located on the Chōfu campus. There is also an early learning center (nursery-kindergarten) for children aged 3–5 located in the Roppongi Hills complex in downtown Tokyo. Instruction is in English and follows an American-style curriculum. About two thirds of the school's students are the children of citizens of a wide variety of countries who are on temporary assignment in Japan, and the remaining one third are Japanese students who speak English. The campus is fenced in, resulting from heightened security measures taken after the September 11 attacks, with campus surroundings including the Nogawa Park and the neighborhood of Tama. The Good Schools Guide International called ASIJ "an impressive school, not only for its size and facilities but also for its strong sense of where it is going."

Chōfu is a city in the western side of Tokyo Metropolis, Japan. As of 1 April 2021, the city had an estimated population of 238,087, and a population density of 11,000 per km2. the total area of the city is 21.58 square kilometres (8.33 sq mi).