An international school is a school that promotes international education, in an international environment, either by adopting a curriculum such as that of the International Baccalaureate, Edexcel, Cambridge Assessment International Education or the International Primary Curriculum, or by following a national curriculum different from that of the school's country of residence.
These schools cater mainly to students who are not nationals of the host country, such as the children of the staff of international businesses, international organizations, foreign embassies, missions, or missionary programs. Many local students attend these schools to learn the language of the international school and to obtain qualifications for employment or higher education in a foreign country. 
The first international schools were founded in the latter half of the 19th century in countries such as Japan, Switzerland and Turkey. Early international schools were set up for families who travelled, like children of personnel of international companies, international organisations, non-governmental organisations (NGO), and embassy staff. The schools were established with the people and organisations having large interests in the hosting nation: for instance, American diplomats and missionaries often set up schools to educate their children: children of American military personnel often attended Department of Defense Dependents Schools (DoDDS). French diplomats and business families founded similar schools based on the French curriculum.
In April 2007 there were 4,179 English-speaking international schools, which was expected to set to rise with globalisation. In New Delhi, worldwide entries for the University of Cambridge International General Certificate of Secondary Education (IGCSE) June 2009 examination session are up by almost 20% on the same session last year. The strong growth confirms the status of Cambridge IGCSE as the world's, and India's, most popular international curriculum for 14- to 16-year-olds. International schooling allows children to become global citizens by providing a rigorous and comprehensive education with full immersion into multiple languages and cultures.
At a conference in Italy in 2009, the International Association of School Librarianship came up with a list of criteria for describing an international school, including:
- Transferability of the student's education across international schools
- A moving population (higher than in state schools or public schools)
- Multinational and multilingual student body
- An international curriculum
- International accreditation (e.g. Council of International Schools, International Baccalaureate, Western Association of Schools and Colleges, etc.)
- A transient and multinational teacher population
- Non-selective student enrollment
- Usually English or French language[failed verification] of instruction, plus the obligation to take on at least one additional language
The most common international schools are based on education in the United Kingdom, education in the United States or are based on curricula specially designed for international schools such as the International General Certificate of Secondary Education or the IB Diploma Programme. These international curricula are committed to internationalism, developing the global citizen, providing an environment for optimal learning, and teaching in an international setting that fosters understanding, independence, interdependence, and cooperation.
Like other schools, international schools teach language arts, mathematics, the sciences, humanities, the arts, physical education, information technology, and design technology. More recent developments specifically for primary school include the IB Primary Years Programme (PYP) and International Primary Curriculum (IPC). Secondary education is provided through the relaunched IB Middle Years Programme (MYP). There are currently[when?] 3063 schools offering the international baccalaureate curriculum in the world  and over 1000 schools offering the IPC around the world.
For expatriate families, international schools allow some continuity in education and most prefer to stay in the same curriculum, especially for older children.
International school associations
British International Schools
COBIS is the Council of British International Schools. Members of COBIS are International Schools across the whole world offering a curriculum which is based on the British system. For older students, ages 14-16 years, this will be the IGCSEs. For 16 to 18 year-olds, this includes the A Level programmes. They will also usually be accredited by a British Based inspection organisation and the inspection reports will be listed on the UK Government website.
Regional International School Associations
Across the world, in addition to global associations such as COBIS, there are also regional international associations such as FOBISIA. FOBISIA is the Federation of British International Schools in Asia. It provides opportunity for teacher training and also students to participate in FOBISIA competitions and workshops across the full range of subjects - Sports, Performing Arts, Model United Nations etc.
International school teachers
An international school teacher or educator is someone engaged in the education of pupils in schools other than their country of citizenship. The term generally refers to teachers who are teaching in private or independent schools. While these schools are private there is an important distinction between private for-profit and private non-for profit schools.
Faculty at international schools are usually from or certified by the standards of their country of origin.
However, there are exceptions, the most common of which the international school requires a teacher trained specifically for an international syllabus or for teaching a foreign language rare to the international school's country of origin.
Hiring is frequently done at large international job fairs, such as the ones held by the Council of International Schools (CIS), where schools can interview and hire several teachers at once. There are also a handful of agencies which specialize in recruiting international teachers. Over the years it has become more difficult to recruit young international teachers, partly because of security concerns and the trend towards less attractive compensation packages. In some countries such as South Korea, recent visa changes have also made it more difficult to obtain both qualified and unqualified teachers.
Hannah Smith of The Guardian wrote in 2013 that many students of international schools move between countries and places constantly. Several reported that they feel they have no one place where they have roots or a background.
ISCResearch have identified (2018 presentation) that in 2017 there were 9,173 international schools, 4.96 million students, 458,000 Staff with this expected to approximately double by 2027 to 16,400 international schools, 10.6 million students, 952,000 Staff.
- International schools
- International school associations and services
- Association of Christian Schools International
- International Schools Services
- United World Colleges
- Nord Anglia Education
- International school teachers
- Examinations and qualifications
- Cambridge International Examinations
- International General Certificate of Secondary Education
- IB Diploma Programme
- "The Importance of International Schools | Ambassador Michael C. Polt". ambassadorpolt.wordpress.com. Retrieved 2016-07-27.
- Teachers International Consultancy (2008-07-17). "The Quiet Crisis in Recruitment". Unihousing. Retrieved 2019-12-19.
- "How to Define an International School". International Association of School Librarianship (IASL). Retrieved 2017-01-12.
- "IB World School statistics". International Baccalaureate Organization. Retrieved 2013-11-29.
- "International Primary Curriculum". Fieldwork Education. Retrieved 2019-07-24.
- Savva, M. (2013). "International schools as gateways to the intercultural development of North-American teachers". Journal of Research in International Education. 12 (3): 214–227. doi:10.1177/1475240913512589.
- "Recruitment Fairs". Council of International Schools.
- "'We have been treated like criminals': South Korea abruptly closes B.C. offshore school | CBC News". CBC. Retrieved 2018-10-30.
- Smith, Hannah. "International school students: rootless and without a home?" (Archive). The Guardian. October 29, 2013. Retrieved on October 20, 2015.