Founded in 1964 through the joint initiative of the International Center for Theoretical Physics and the Italo-American Association, the International School of Trieste is a not-for-profit, English language school for day students of all nationalities. IST is accredited by The Middle States Association of Schools and Colleges (M.S.A.), and is a member of the European Council of International Schools (E.C.I.S.), to the Council of International Schools (C.I.S.), to the Association for the Advancement of International Education (A.A.I.E.) and the Mediterranean Association of International Schools (M.A.I.S.).

IST is located in the quiet greenery of the Villaggio del Fanciullo in the Carso town of Opicina, a pleasant suburb of Trieste. The student population of over 300 pupils, comprising about 25 nationalities, is drawn from the city of Trieste and the surrounding provinces. All teachers are highly qualified and recruited worldwide to provide a quality International education for students aged 2-16+.