John Brown Lennon (October 12, 1850 - January 18, 1923) was an American labor union leader and general-secretary of the Journeyman Tailors Union of America (JTU). In 1890, he was elected treasurer of the American Federation of Labor and served in that capacity until he was defeated by Teamsters president Daniel J. Tobin in 1917. During World War I, he was appointed by Woodrow Wilson to the U.S. Department of Labor's board of mediators and Commission of Conciliation, and also served on the U.S. Commission of Industrial Relations. In 1919, he supported the formation of the Illinois Labor Party and ran for mayor of Bloomington, Illinois on the Labor Party ticket.