Yokohama International School was established in 1924, shortly after the 1923 Great Kantō earthquake by a group of foreign residents in Yokohama. The first class was held on 27 October 1924 with only 6 students. By 1939, it had 110 students from 21 nationalities, but was forced to close due to World War II. The original school structures were destroyed during the bombing of Yokohama in World War II. After the war, the school was reopened in 1955 on its original site. The school continued to expand in both facilities and enrolment through the 1960s and 1970s, and initiated its first International Baccalaureate Diploma Programme from 1986. It became fully accredited in 1991 by the European Council of International Schools and the New England Association of Schools and Colleges. Presently, the school has a student body of over 700 comprising over 50 nationalities and faculty and staff of over 100 spanning 15 nationalities.
Cafeteria The Cafeteria is 216m2 and is able to hold 120 people. There are enough tables and seats for up to 100 people, a sound system, pull-down screen and a projector. Bathrooms The Bathrooms are located on the 2nd and 3rd floors of the main building. Bathrooms are also located in the gymnasium, the kirin building, the modern languages building and the cafeteria. Tanner Auditorium The Tanner Auditorium is 301.95m2 and is able to hold 250 people. It is equipped with movable bleacher seating for up to 240 people, platform risers for the stage, movable chairs for up to 110 people, tables, a sound system, lighting equipment, concert piano, music stands, pull-down screen and a projector. Gymnasium The Gymnasium is 476m2 and is equipped with changing rooms, along with basketball, volleyball, badminton, pingpong, dodgeball, and hockey equipment Dance Studio The Dance Studio is 116.23m,2 and is able to hold around 40 people. It is equipped with changing rooms, a sound system along with various exercise mats. Outdoor Turf The Outdoor Turf is 595m2 and is able to hold around 25 people. It is equipped with soccer balls, hockey equipment, portable goals, and a roof netting. Playground The Playground is 336m2 and is in front of the elementary building and the cafeteria. It is equipped with basketballs, hoops, soccer balls, and a PA System. The elementary building is equipped with shock resistant glass to ensure the safety of elementary students.