The race features incumbent county commissioner Ray Barber and challenger Charles Thaxton, a former member of the Polk School District Board of Education.
Barber and Thaxton finished in the top two of a crowded primary ticket, which also included former commissioners Ricky Clark and Phillip Bentley.
Neither Barber or Thaxton were able to garnish a majority in the primary, which forced the runoff.
The winner of the GOP runoff will determine who will be the lone candidate on the ballot in the November General Election as no Democrats or Independents qualified in the election.
Voters can vote from 7:00 a.m. to 7:00 p.m. at their respective polling places.