Seoul International School provides facilities that promote an excellent environment for optimum learning and teaching. Information and communication technology within the school is constantly being upgraded with five computer labs for student use. All classrooms and facilities are fully networked. There are two spacious and well-resourced libraries, with computer access, and several well-equipped science laboratories.
The school auditorium, used for school assemblies, teacher and parent functions, fine arts productions and concerts, is fully equipped with lighting and sound systems. Music students are offered a range of facilities from band and choir rooms to sound proofed practice rooms.
Athletic facilities include two gymnasiums, a tennis court, a five-lane indoor 25-meter heated swimming pool, soccer field, and weights and gymnastics rooms. Available for elementary student use during lunch and recess times are modern outdoor play areas. For the comfort of students and staff, the school buildings are fully air-conditioned in summer. The school cafeteria, offering nutritious hot meals or lighter sandwiches daily allows students to eat in the company of friends and peers.