Jerzy Ksawery Franciszek Sosnowski (December 3, 1896 in Lwów – 1942, 1944 or 1945 in Poland or the Soviet Union) was a major of the Second Department of the General Headquarters of the Polish Army (called Dwójka) and a Polish spy in Weimar Germany (1926–1934), using pseudonyms Georg von Nalecz-Sosnowski and Ritter von Nalecz.
In the Soviet Union, he was known as Jurek Sosnowski, some sources present his name as Stanislaw Sosnowski.