John R. Fellows (July 29, 1832 in Troy, Rensselaer County, New York – December 7, 1896 in New York City) was an American lawyer and politician from Arkansas and New York.
He was the son of Tisdale Eddy Fellows (1800–1874), farmer, and later Superintendent of the Halfmoon Cemetery, and Eliza (Harris) Fellows (1809–1867). The family moved to a farm in Stillwater in Saratoga County, New York, where he attended the country schools. Among his playmates was Elmer E. Ellsworth.
In 1850, Fellows went to Camden, Ouachita County, Arkansas, to live with his uncle. There he studied law and was admitted to the bar in 1855. At one time he practiced law in partnership with Walter L. Bragg.
He ran for presidential elector on the Constitutional Union ticket of Bell and Everett in 1860, but Arkansas was carried by John C. Breckinridge. He was a delegate to the State secession convention in 1861.
He enlisted in the 1st Arkansas Infantry of the Confederate States Army. After the Battle of Shiloh, he was made a colonel and assigned to staff duties as assistant adjutant to Gen. William Beall. Later he was inspector general at Port Hudson, Louisiana, and was captured there on July 9, 1863. He was kept a prisoner of war until the end of the American Civil War, and released on June 10, 1865. Afterwards he resumed the practice of law in Camden. He was a member of the Arkansas Senate from 1866 to 1867. On July 4, 1867, he married Lizzie Reynolds, and they had six children.