Frank James McGarr (born February 25, 1921) is a former United States federal judge.
Born in Chicago, Illinois, McGarr received an A.B. from Loyola University Chicago in 1942, and was in the United States Army for the remainder of World War II, from 1942 to 1945. He received a J.D. from Loyola University Chicago School of Law in 1950. He was an Assistant to the president, Loyola University, Chicago from 1946 to 1952. He was in private practice in Chicago, Illinois from 1952 to 1954. He was a First assistant U.S. attorney of Northern District of Illinois from 1954 to 1958. He was in private practice in Chicago, Illinois from 1958 to 1969. He was a First assistant state attorney general of Illinois from 1969 to 1970. Private practice, Chicago, Illinois, 1988–present.
McGarr was a federal judge on the United States District Court for the Northern District of Illinois. McGarr was nominated by President Richard Nixon on September 22, 1970, to a new seat created by 84 Stat. 294. He was confirmed by the United States Senate on October 8, 1970, and received his commission on October 14, 1970. He served as chief judge from 1981-1986. He assumed senior status on June 30, 1986. McGarr served in that capacity until January 15, 1988, due to retirement.