Kazimierz Romuald Mijal (September 15, 1910 – January 28, 2010) was a Polish communist politician and dissident, best known for founding the illegal Communist Party of Poland (Mijal) in opposition to the Polish United Workers' Party (PUWP) in 1965.

Born in to a poor peasant family, he Graduated from a Tradesmen's Association Commercial School in Warsaw.

After marrying the communist activist and painter Jadwiga Gniewkowska, Mijal became politically active during World War II and joined the Polish Workers' Party, collaborating with Paweł Finder, Marceli Nowotko and Bolesław Bierut.

After the end of the war and the creation of the Polish People's Republic Mijal held various positions in the party and the state.

He created various pamphlets condemned by the party as "dogmatic and Stalinist", and used a fake passport to leave for Albania, whose leader Enver Hoxha led the anti-revisionist movement along with Mao Zedong.