Cyryl Ratajski (3 March 1875, Zalesie Wielkie - 19 October 1942, Warsaw) was a Polish politician and lawyer.
He was the president (mayor) of Poznań in the years 1922-1924, 1925-1934 and in September 1939. In the years 1924-1925 he was the Polish Minister of the Interior.
From 1937 he was a member of Labour Party, Stronnictwo Pracy. Voivode of the Poznań Voivodeship in 1939.
During World War II he was the first Head of Delegate's Office of the Polish government in exile (Delegat Rządu na Kraj), in the years 1940-1942.