Granville Gaylord Bennett (October 9, 1833 – June 28, 1910) was an American lawyer who served as a justice of the Supreme Court for the Dakota Territory and as a delegate to the United States House of Representatives.
Granville was born near Bloomingburg in Fayette County, Ohio. His family moved to Fulton County, Illinois in 1849, and then to Washington, Iowa in 1855. He attended Washington College, an academy in Washington, Iowa, and then studied law. He was admitted to the bar in 1859, and practiced in Washington.
During the American Civil War he served in the Union Army, first as an officer in the 19th Iowa Volunteer Infantry Regiment, and later on the staff of Thomas J. McKean, commander of the Army of the Tennessee. Following the war, he was discharged as a first lieutenant and returned to Washington, Iowa. He served as a member of the Iowa House of Representatives (1865–1867) and Iowa State Senate (1867–1871).
Bennett moved to the Dakota Territory and was appointed an associate justice of the Supreme Court of the Territory in 1875. He was elected as the Territory's non-voting Delegate to the U.S. Congress, and served as a Republican from March 4, 1879 – March 3, 1881. He was not a candidate for reelection in 1880.
Bennett moved to Deadwood, South Dakota, where he practiced law, then was elected judge of the probate court of Lawrence County and served three terms. He died in Hot Springs, Fall River County, South Dakota. He was interred in Mount Moriah Cemetery, in Deadwood.