ISOI encourages its students to become involved in athletics and provides a wide variety of choices in team and individual sports, varsity, middle school, and intramural athletics, as well as regular physical education classes. 

ISOI is a member of the South Asia Inter-School Association (SAISA) and competes with other international schools in Pakistan, India, Sri Lanka, Nepal, and Bangladesh.  Tournaments are held in soccer, volleyball, basketball, track and field, cricket, tennis, and swimming.