Kazimierz Kordylewski (born 11 October 1903 in Poznań – 11 March 1981 in Kraków, Poland) was a Polish astronomer. In 1956, he claimed the discovery of the Kordylewski clouds, large transient concentrations of dust at the Trojan points of the Earth–Moon system, which were reported to have been confirmed to exist in October 2018. He studied at University of Poznań and Jagiellonian University, and earned a PhD degree in 1932.