Leon Piniński (8 March 1857 - 4 April 1938) was a Polish scientist, diplomat, art historian and politician. A professor of Roman law and one-time rector of the Lwów University (1928–1929), he devoted most of his life to political career in his hometown of Lwów (modern Lviv, Ukraine), initially in Austria-Hungary and then in Poland.
Leon Piniński was born in Lwów, then in Austro-Hungarian Galicia. An heir to Piniński aristocratic family (holding the rank of hrabia - Count), he was also the owner of the Grzymałów manor. After receiving basic education at home, he passed his matura exam at the renowned college of Tarnopol. He then graduated from the Faculty of Law of the Lwów University. Piniński also continued his studies in Leipzig, Berlin and Vienna. In 1891 he became a professor of Roman law at his alma mater and soon afterwards he was admitted to the Polish Academy of Skills.
However, soon afterwards he gave up his scientific career and devoted himself to local politics. A member of the Podolacy aristocratic faction, he soon became one of the most popular conservative politicians of Lwów. In 1889 he was elected to the Imperial Council in Vienna. In addition to that, in 1894 he was also elected to the Galician Sejm. His term in both offices ended in 1898, when he became the governor of the province of Galicia. During his term in that office he became engaged in a struggle against the growing popularity of Socialist ideas. He also tried to counter the rise of Ukrainian nationalism. Extremely conservative, in 1903 he was dismissed from that post and replaced with Andrzej Kazimierz Potocki, a liberal and rich industrialist and a mogul.