The Oklahoma State Department of Health reported on Thursday 603 new cases of COVID-19, bringing the state's total to 18,496.
It was the state's third-highest number of new cases, following its biggest increase so far on Tuesday and its second-biggest jump yesterday.
Tulsa County had 122 of the new cases, increasing its total to 4,693.
The state's seven-day average of new cases, a measure of the trend in new infections, hit another high Thursday at 565. Tulsa County's declined slightly, from 147 to 145.