Voters in northwest Tulsa and southeast Osage County will be selecting the person to fill a vacant state House seat.
Polls are open until 7 p.m. Tuesday for the special election in House District 73.
Seven Democrats are running for the seat left vacant when Democrat Kevin Matthews left to run for an open state Senate seat, which he won.
The candidates are Robert Lewis, Jonathan Townsend, Norris Minor, Jeanetta Williams, Regina Goodwin, Joe Williams and Jennettie Marshall.
The race is actually a Democrat primary, but since no Republicans or independents filed to run, whoever gets the most votes on Tuesday will win the seat.
The Associated Press contributed to this report.