Jaroslav Bohdan Rudnyc'kyj was born to Ukrainian parents on November 28, 1910 in Przemyśl (Peremyshl') Austro-Hungarian Empire (now Poland). Rudnyckyj graduated with a Ph.D. from the University of Lviv in 1937, specializing in Slavic philology and the onomastics (geographical place names) of eastern Europe. To continue these and other studies abroad, he left his homeland in 1937, staying for short periods in Berlin, Munich, Rome, and Paris before lecturing in Slavic philology at the Ukrainian Free University, at Charles University in Prague, and at the University of Heidelberg. In 1949, shortly after his immigration to Canada, he was appointed Chairman of the new Department of Slavic Studies at the University of Manitoba, a position he held until 1976. He was also a co-founder of the Canadian branch of the Ukrainian Free Academy of Sciences (UVAN) in Winnipeg, serving as its president (1955-1970).

From 1963 to 1971, Rudnyckyj was a member of the Canadian Royal Commission on Bilingualism and Biculturalism where he promoted the idea of a multilingual Canada. Rudnyc'kyj not only published widely and extensively but was also instrumental in developing a major Slavic collection for the University of Manitoba Libraries. He was interested in the philologies and literatures of East European languages, in the Slavic experience in Canada, and in the origin of place names. Rudnyc'kyj's publications consist of hundreds of articles and reviews, etymological dictionaries, translations, travel diaries, and onomastic studies. Rudnyc'kyj died in Montreal, Quebec on October 19, 1995.