Many hopefuls threw their hats in the ring to replace outgoing Oklahoma Governor Mary Fallin who had reached her term limit.
A runoff is anticipated in the Republican primary with 10 candidates splitting the vote. To avoid a runoff, one of the candidates would have to receive 50 percent of the vote - plus one.
Republican candidates are: Todd G. Lamb, Barry Gowdy, Blake "Cowboy" Stephens, Gary A. Jones, Mick Cornett, Gary Richardson, Christopher Barnett, Dan Fisher, Eric Foutch and Kevin Stitt.
Democrats running for the state's top office are Drew Edmondson and Connie Johnson.
Joe Exotic, Rex Lawhorn and Chris Powell are running on the Libertarian ballot.
In exclusive News On 6 polls conducted earlier this year, former Oklahoma City Mayor Mick Cornett and Lieutenant Governor Todd Lamb were favored by voters.
Drew Edmondson held a strong lead among those polled.