Cezaria Jędrzejewiczowa or, Cezaria Anna Baudouin de Courtenay Ehrenkreutz-Jędrzejewiczowa (1885 – 1967) was a Polish scientist, art historian and anthropologist. She was one of the pioneers of ethnology in Poland and one of the first scientists to adopt phenomenology in studies on the folk culture.
She was born on 2 August 1885 in Dorpat (modern Tartu, Estonia), to Jan Niecisław Baudouin de Courtenay, a noted linguist, and his second wife Romualda née Bagnicka. Between 1927 and 1935 she served as a professor and founder of the chairs of ethnography and ethnology at the Stefan Batory University of Wilno (modern Vilnius, Lithuania). In 1935 she moved to the same post at the Warsaw University and occupied it until the Nazi-Soviet invasion of Poland.
Initially married to her father's student Max Vasmer, she divorced him and remarried Stefan Ehrenkreutz, a professor of law and a senator of Poland. She divorced him as well and married for the third time. Her husband, Janusz Jędrzejewicz, was a former Prime Minister of Poland. During World War II she escaped from Poland and settled in the British-held Palestine, where she co-founded the Polish Scientific Institute of Jerusalem, a sort of an exiled university for the soldiers of the Polish II Corps. In 1947 she moved to Great Britain, where she became one of the founding members of the Polish Scientific Society in Exile. In 1951 she became a professor of ethnography at the Polish University in Exile and soon afterwards was chosen its rector.
Jędrzejewiczowa died on 28 February 1967 in London at the age of 82.