Jaroslav Krejčí (February 13, 1916 – February 16, 2014) was a Czech-British sociologist, historian, economist and former professor of sociology at Lancaster University.
Krejci was born on February 13, 1916, in Polešovice, Austria-Hungary (the present-day Czech Republic). He studied law.
Krejci's father, Jaroslav Krejčí, held office as the Prime Minister of the German-occupied Protectorate of Bohemia and Moravia from 1942 to 1945. In contrast to his father's collaboration, Jaroslav Krejci opposed the German occupation of Czechoslovakia and became actively involved in the Czech resistance during World War II.
Krejci joined the Josef Hlavka National Economic Institute after the end of the war. He openly opposed the merger of the Czechoslovak Social Democratic Party, to which he was a member, into Communist Party of Czechoslovakia following the 1948 Czechoslovak coup d'état. In 1954, he was sentenced to ten years in prison on charges of treason for his opposition to the Communist Party.
He was released from prison in 1960 as part of an amnesty. He and his wife immigrated to the United Kingdom following the Warsaw Pact invasion of Czechoslovakia in 1968, which had crushed the Prague Spring. Krejci became a professor of sociology at Lancaster University. He taught in the university's Departments of French Studies, German Studies and Religious Studies from 1969 until 1983. Much of his research focused on history and the formation of civilization from a macrosociological approach. He returned to Czechoslovakia and the Czech Republic following the fall of communism to teach at Charles University in Prague and Palacký University, Olomouc, as well as the Diplomatic Academy of Vienna.