Governor Gavin Newsom announced the news during a press conference today.
"This individual, who is a resident of San Francisco, was fully vaccinated, had recently been in South Africa, began they're travels back into the United States on [November] 21st, landed on the 22nd, developed some symptoms a few days later around the 25th, got tested on the 28th. The test came back positive on the 29th," Newsom said.
Newsom said the person was vaccinated but had not received a booster.
The news comes as scientists continue to study the risks posed by the new strain of the virus.
To help prevent spread of the variant, state officials say they're increasing COVID testing at airports for arrivals from countries identified by the Centers for Disease Control.