Casimir Lewy (Polish: Kazimierz Lewy; 26 February 1919 in Warsaw – 8 February 1991 in Cambridge) was a Polish philosopher of Jewish descent.
He worked in philosophical logic but published scantly.
According to Ian Hacking, "He had early acquired the conviction that one should publish only when one got something absolutely right, so he left very little in print." He was an influential teacher; several of his students went on to be prominent philosophers, including Simon Blackburn, Edward Craig, Ian Hacking, Roger Scruton, and Crispin Wright.