The 1942 Tennessee gubernatorial election was held on November 3, 1942. Incumbent Democratic governor Prentice Cooper defeated Republican nominee C. N. Frazier with 70.2% of the vote.
In the Democratic primary, Judge John Ridley Mitchell, who despised Memphis political boss E. H. Crump, sought the party's nomination for governor but was defeated by Cooper, 171,259 votes to 124,037.
In 1942, the federal government appropriated land in what is now Oak Ridge, Tennessee, for the top secret Manhattan Project which was developing the world's first atomic bomb. Cooper was not informed of the purpose of the project. When Anderson Countians complained to Cooper of land appropriations, Cooper accused the federal government of stealing the land for a "socialist" project. When officially notified in July 1943 by an Army lieutenant of the presidential proclamation making the area a military district not subject to state control, he angrily ripped it to pieces. The new MED District Engineer Lieutenant Colonel Kenneth Nichols had to placate him.
Along with defense mobilization, Cooper increased funding for state schools and implemented a program that provided free textbooks for children in grades 1 through 3. He increased aid to the elderly, established a system of tuberculosis hospitals, and acquired land for state parks and state forests. He cut the state payroll and placed taxes on alcohol, and he managed to reduce the state debt by $21 million. In January 1941, a Cooper-supported bill calling for a repeal of the state's poll tax was introduced in the state legislature but was defeated. In 1943, the repeal passed but was thrown out by the Tennessee Supreme Court.
Primary elections were held on August 6, 1942.