Stewart Brett McKinney (January 30, 1931 – May 7, 1987) was an American politician who represented the fourth congressional district of Connecticut in the House of Representatives from 1971 until his death.
McKinney was born in Pittsburgh, Pennsylvania, but by the time he graduated from high school, his family was living in Connecticut, where he would live for the rest of his life. After attending Princeton University from 1949 to 1951, he dropped out and enlisted in the U.S. Air Force, where he attained the rank of sergeant. After leaving the Air Force in 1955, he went back to college, receiving a B.A. from Yale University in 1958.
In 1966, McKinney was elected as a Republican to the Connecticut State House of Representatives, where he served two 2-year terms, including a stint as minority leader in his second term (1969–1970). In Congress, he served on the House Select Committee on Assassinations. During this time, he also served as a director of Bridgeport Hospital.