Tadeusz Estreicher (19 December 1871 – 8 April 1952) was a Polish chemist, historian and cryogenics pioneer.
Tadeusz Estreicher was born in Kraków when it was part of the Austrian-Hungarian Empire. He grew up in the intellectual atmosphere of an influential dynasty of professors at the Jagiellonian University. His father, Karol Józef Estreicher, was a historian of literature and the chief librarian of the university. His brother, Stanisław, was a historian of law and his sister, Maria, was one of the first women in Austria-Hungary to earn a doctorate (in English Philology).
Estreicher studied in Berlin, Leipzig, and in London under William Ramsay. As a student at the Jagiellonian University, Estreicher worked as an assistant to Karol Olszewski, the first chemist to liquefy oxygen. After having been appointed assistant in 1899, Estreicher successfully liquefied hydrogen in 1901 before he was promoted to Privatdozent in 1904.
In 1900, he described the Jagiellonian globe in the Transactions of the Cracow Academy of Sciences.
From 1906 until 1919 he worked in Switzerland a professor for mineral and general chemistry at the University of Fribourg where he ran a cryogenics laboratory. From 1913 to 1914 he also served as dean of the department.
In 1919, aged 47, he returned to newly independent Poland and took a position with the Jagiellonian University where he remained until his retirement. His later work examined the history and language of science.