Teaching career began at the History Department at Harvard University (1973-1975), continued in Hamiltonskomu University in New York (1976-1981) and at York University (Canada, from 1982 Professor of History and Political Science), where he teaches now.
In 1975 by Ukrainian Free Academy of Sciences (UVAN) published work "Letters of Ivan Mazepa. Published by Columbia University in 1981 published a monograph "Mazepintsy: Ukrainian Separatism XVIII century.". In 1985 was published the monograph "The problem of domination in Eastern Europe: local notables and foreign absolutism. 1500-1715.
In 1996 Orest Subtelny was elected a foreign member of the National Academy of Sciences of Ukraine, December 22, 2006 awarded an honorary doctorate at the Diplomatic Academy of Ukraine Ministry of Ukraine.
The biggest recognition of Orest Subtelny brought job Ukraine: History, first published in 1988 publishing the University of Toronto. It was recognized as one of the most influential and important books that were published by the University of Toronto 100 years of its existence. Ukrainian language book was published in 1991, it withstood repeated issue. Translated in whole or in parts in other languages: German, Russian, Chinese, Bulgarian and Slovak.
