The East Asia Regional Council of Overseas Schools is an organization of 105 member schools in East Asia. These schools have a total of more than 54,000 pre-K to 12th grade students. EARCOS also has 86 associate members— textbook and software publishers and distributors, universities, financial planners, architectural firms, insurance companies, youth organizations, etc— and over 33 individual members.

Membership in EARCOS is open to elementary and secondary schools in East Asia which offer an educational program using English as the primary language of instruction, and to other organizations, institutions, and individuals interested in the objectives and purposes of the Council.