Oleg Yesayan (; born 12 November 1946) is an Armenian politician and diplomat who is a former Prime Minister of Nagorno-Karabakh, President of the National Assembly of Nagorno-Karabakh, and Chairman of the Securities Commission of Armenia. Yesayan is also a former ambassador of Armenia to Russia and Belarus, presenting his credentials to Russian president Dmitry Medvedev on 5 February 2010.