Stanisław Estreicher (26 November 1869 – 28 December 1939) was a Polish historian of Law and bibliographer.
Stanisław Estreicher grew up in the intellectual atmosphere of an influential professorial dynasty at the Jagiellonian University. His father, Karol Józef Teofil Estreicher, was a leading historian of literature and the University's head librarian. His brother Tadeusz was a chemist and pioneer in cryogenics. His sister Maria was one of the first women in Poland to earn a doctorate (in English philology). Stanisław Estreicher’s son, Karol Estreicher, Jr., was one of the most important historians at the University and founder of the Jagiellonian University Museum. His daughter, Krystyna Grzybowska, was a children's-book writer and historian.
After studying at Kraków and Vienna, Estreicher earned his “habilitation” in 1894 and became a professor of the Jagiellonian University in 1906. Among his circle of associates was a young doctoral candidate, Bronisław Malinowski. In 1911, 1918 and 1926, Estreicher was the Dean of the Faculty of Law. In 1919 he was elected Rector of the University and served until 1921. After the death of his father Karol Józef in 1908, he attempted to complete his father’s unfinished Bibliografia Polska (begun in 1870), a massive reference work on all significant Polish authors from the 15th to the 19th century.
His work was cut short on 6 November 1939, when along with his brother Tadeusz and other professors of the University, Estreicher was caught in Sonderaktion Krakau. Both were transported to Sachsenhausen concentration camp, where Stanisław Estreicher died on 28 December 1939 of uremia caused by the difficult conditions in the camp. His family was not informed until 13 January 1940 and his funeral was not held until 28 July 1940.
His wife, Helena née Longchamps, died in March 1940. His son, Karol Jr., would later complete the Bibliografia Polska.