In 1981, expatriate families began a cooperative to educate their children from a biblical worldview. The cooperative continued for 12 years, providing first grade to sixth grade education. In 1990 many of these expatriate families and The Network of International Christian Schools met to discuss the feasibility of establishing a Christian school to provide kindergarten through twelfth grade education to the English speaking international community in Bangkok. In 1993 a suitable site was leased and the name International Community School (ICS) was chosen. The school was located on Soi Prong Jai in the Sathon area of Bangkok and welcomed 120 students when it opened in August 1993. The school's ownership was given to, and remains with the International Community School Educational Foundation, a not-for profit foundation registered in Thailand.
In 1998, ICS received accreditation from two U.S. based accrediting agencies: The Western Association of Schools and Colleges and The Association of Christian Schools International. The school expanded each year until it offered a K-12th grade education. The ICS community celebrated its first graduating class in 1998.
In 2002, the local school board of International Community School chose to become independent of the Network of International Christian Schools in favor of governance by its local school board.
ICS enrollment consistently increased and outgrew the leased facility, despite several on-site building projects. The ICS Educational Foundation Board and the ICS administration, with the generous support of the families of ICS, purchased the current 16.2 rai plot of land in Bangna and began building in 2003. International Community School opened the Bangna campus in September 2004 with close to 500 students in four-year-old kindergarten through twelfth grade. The original campus at Soi Prong Jai was closed in June 2007.
ICS continues the tradition of offering quality Christian education for the international English speaking community and now educates over 1000 students from over 22 nations.