The 1918 Arizona gubernatorial election took place on November 5, 1918, for the post of the Governor of Arizona. Thomas Campbell, who served a partial term in 1917 and had his election overturned by the Supreme Court of Arizona, returned to contest the Governors office. Incumbent Governor Hunt declined to run again after the stress of the close elections and the year-long court battle. Despite falling to its lowest percentage in years, the sole third party challenger held the difference between the two candidates. The Democratic challenger was state senator Fred T. Colter, a pro-Hunt Democrat.

Fred Tuttle Colter was an Arizona rancher and farmer, as well as being the state senator for Apache County beginning with Arizona's second state legislature in 1915. Colter spent six terms in the Arizona Senate. He also led the fight on Arizona's behalf to maintain control over the water from the Colorado River, coining the slogan, "Save the Colorado for Arizona". He was a close ally of the state's first governor, George W. P. Hunt. Prior to his election to the state senate, Colter had served as the state's fair commissioner.