Kelly was born on December 7, 1875, in Poplar Bluff, Missouri, son of George H. and Helen Kelly. The family moved to Austin, Texas in 1881, and then moved on to Clifton, Arizona in 1885, and then Tucson the following year. In 1890 they moved to Solomonville, where George purchased the local paper, The Solomonville Bulletin.[2] By 1898 he was working for his father at the Solomonville Bulletin. He also married that same year, on February 22, to Ruth Guernsey.[3][4][5] Their children included William Henderson Kelly, who also became a newspaperman and later a noted anthropologist of the American Southwest.[6]
In 1930, Kelly ran for and won the Arizona State Senate for the single seat from Graham County.[13] He ran for re-election in 1932 and won.[14] He chose not to try for re-election again in 1934, instead challenging incumbent James H. Kerby in the Democrat primary for Arizona Secretary of State, but was defeated in a five-man race, coming in second.[15] In 1938 Kelly once again ran for the State Senate. He was unopposed in both the Democrat primary and the general election in November.[16][17] He did not run for re-election in 1940, instead joining Governor Robert Taylor Jones' staff in 1939 as his executive secretary.[18]
Kelly sold the Graham Guardian in 1943 to the Gila Printing and Publishing Company, a newly formed company.[19] In January 1944, Kelly sold The Copper Era, the last of his paper interests.[11] Kelly died on February 14, 1948, in the Elks State Hospital in Tucson. He had come to the hospital in ill health the prior week.[2][18]