Reidar Friis Bull (7 May 1909 – 1994) was a Norwegian judge. He was a son of Trygve Bull (1870–1958), brother of Trygve Bull and Brynjulf Bull and uncle of Bernt Bull. He married Eline Pedersen in 1945. He finished his secondary education in 1927 and the cand.jur. degree at the Royal Frederick University in 1932. From 1934 to 1936 he was a junior solicitor for Emil Stang. He was also a member of the communist group Mot Dag. Bull also chaired the Norwegian Students' Society in 1940, and later the Socialist Jurist Association from 1948 to 1949 and 1961 to 1963.