The patient had recently returned from Wuhan, China – epicenter of the outbreak that is believed to have killed at least 56 people — and was in a hospital in good condition by Saturday evening, the agency said in a statement.
Officials didn’t provide details about the infected patient but said there’s no evidence anyone else in Orange County was exposed to the highly contagious virus.
The California case comes after two others reported in the Seattle and Chicago areas last week. Both of those patients were reportedly still in isolation.
Canada, Australia and Malaysia also reported their first cases Saturday.
The novel virus has also sickened nearly 2,000 people.
Most coronaviruses cause only mild symptoms, similar to those of the common cold. Other strains, such as Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS), can cause pneumonia and death.
The California case was initially confirmed by the Saturday by the federal Centers for Disease Control and Prevention, which contacted Orange County officials.
There is no vaccine to protect against the virus, although the National Institutes of Health confirmed to Fox News that they were in the “early stages” of developing one, and officials were hoping a lockdown placed on 13 cities in China and elsewhere would help contain the virus from spreading further.
Fox News’ Nick Givas contributed to this report.