Since the first local case was identified in March of 2020, county officials say a total of 803,293 cases have been recorded.
Recently, county health officials say that weekly coronavirus cases have tripled over the past month, with hospitalizations also on the rise.
The new total case count includes 4,428 cases reported in the past three days.
Get San Diego local news, weather forecasts, sports and lifestyle stories to your inbox. Sign up for NBC San Diego newsletters.
"The somber milestone and recent spike in cases should serve as a reminder this isn't the time to let our guard down," said the county's deputy public health officer Cameron Kaiser. "Please, make sure you're up to date on your vaccinations and boosters, and consider a mask, especially if you're medically vulnerable yourself or may be around people who are."
The county also reported 12 more COVID-19 deaths on Thursday, which occurred between Feb. 4 and June 5. Four of those deaths happened in the past two weeks.
Nine of the people who died were 80 years or older, two were in their 70s and one in their 60s. Five of those people were fully vaccinated, while the other seven were not fully vaccinated, though 11 of those people had underlying medical conditions.
The region's total death count is 5,315.