Greenbury Lafayette Fort (October 17, 1825 - January 13, 1883) was a U.S. Representative from Illinois.
Born in French Grant, Ohio, Fort moved with his parents to Marshall County, Illinois, in April 1834. He completed preparatory studies and attended Rock River Seminary. He studied law. He was admitted to the bar in 1847 and commenced practice in Lacon, Illinois.
Fort was elected sheriff in 1850. He served as clerk of Marshall County in 1852. County judge in 1857. He was appointed a second lieutenant in the Eleventh Regiment, Illinois Volunteer Infantry, on April 30, 1861. He was promoted through the ranks to lieutenant colonel and quartermaster. Brevetted major and lieutenant colonel of Volunteers March 13, 1865. He served as member of the State senate in 1866.
Fort was elected as a Republican to the Forty-third and to the three succeeding Congresses (March 4, 1873-March 3, 1881). He was not a candidate for renomination in 1880. He retired from public life. He died in Lacon, Illinois, January 13, 1883. He was interred in Lacon Cemetery.