Kazimierz Bartel (1882-1941), was a Polish mathematician and politician; Prime Minister of Poland,1926-1930.

He was born in Lemberg (Lw&oacute'w, in Polish) March 3, 1882. After completing secondary school he studied at the Lwów Polytechnic in the Mechanical Engineering Department. He graduated in 1907 and soon became an assistant in Descriptive Geometry. By 1914 he was a professor at his alma mater.

Conscripted into the Austro-Hungarian army during World War I, in 1918 he returned to Lwów. In 1919, as commander of railway troops, he fought in the defense of Lwów against the Ukrainian siege.

Appointed minister of railways in 1919, in 1922-1930 he was a member of Poland's Sejm (parliament). After Józef Piłsudski's May coup d'etat (1926) he became prime minister and held this post for four years. In 1930 he gave up politics and returned to academia. In 1930 he became rector of the Lwów Polytechnic and was soon awarded an honorary doctorate and membership in the Polish Mathematical Association.

In this period he published his most important writings, among them a series of lectures on perspective in European painting throughout the ages. In 1937 he was appointed a senator of Poland and held this post until the war broke out.

After the Soviet occupation he was allowed to continue giving lectures at the, now renamed, Lvov Polytechnical Institute. In 1940 he was appointed to Moscow and offered a seat in the Soviet parliament. He refused and returned to Lvov.

Soon after the German invasion of the Soviet Union, on June 30 1941 the Wehrmacht entered Lvov. Kazimierz Bartel was arrested two days later and imprisoned in Gestapo prison. He was offered to create a Polish puppet government. He refused and, by order of Heinrich Himmler, was shot on July 26, 1941. His place of burial remains unknown.

|- style="text-align: center;" | width="30%" |Preceded by:
Józef Pilsudski | width="40%" style="text-align: center;" |Prime Minister of Poland
1928–1929 | width="30%" |Succeeded by:
Kazimierz Switalski

|- style="text-align: center;" | width="30%" |Preceded by:
Kazimierz Switalski | width="40%" style="text-align: center;" |Prime Minister of Poland
1929–1930 | width="30%" |Succeeded by:
Walery Slawek