Marian Zyndram-Kościałkowski (Polish pronunciation: [ˈmarjan ˈzɨndram kɔɕt͡ɕawˈkɔfskʲi]; 16 March 1892, Pandėlys, Kovno Governorate – 12 April 1946 Brookwood, Surrey) was a Polish politician, freemason and military officer who served as voivode of Białystok Voivodeship in 1930-1934, Mayor of Warsaw in 1934 and 27th Prime Minister of Poland from 1935 to 1936.
Marian Zyndram-Kościałkowski was born in his family’s real estate of Pandėlys, located in the Novoalexandrovsky Uyezd of the Kovno Governorate of the Russian Empire (today Lithuania), to Karol and Maria Budrewicz. He came from a noble background that used the Syrokomla coat of arms. In 1903, Marian went to Saint Petersburg where he attended middle and high school. After graduation in 1910, he began studying at the local Neurological Institute. Also, he studied agriculture at Riga Technical University.
In 1911, Zyndram-Kościałkowski became a member of the Union of Active Struggle (ZWC), Polish independence organization. Together with Walery Sławek, he was a co-founder of structures of the ZWC in northwestern corner of the Russian Empire. In 1912, he was named commandant of the ZWC in the Baltic provinces of Russia, and in the summer of 1914, after the outbreak of World War I, he planned to join Polish Legions in World War I, but was ordered to stay in Warsaw. In 1915, he joined Polish Military Organisation (POW), using nom de guerre Jerzy Orwid. On February 7, 1915, Józef Piłsudski promoted him to Podporucznik (Second Lieutenant). In the same year, he married fellow member of the POW, Anna Krysińska. In 1918, their son Witold was born, with Piłsudski as the godfather.