BA will begin the service between Oakland and Gatwick on March 28, and another service between Gatwick and Fort Lauderdale on July 6, competing with discount carrier Norwegian on both routes.
BA’s new Oakland route will be its first from Gatwick to California, and its fifth service from London to the state.
San Francisco which is a 30-minute train journey or a 35 minute drive by car.
The route will be served by a 777-200ER aircraft operating four-days a week, with flights launching from £189 each way.
Colm Lacy, British Airways’ head of commercial at Gatwick, said: “We’re very excited to open up California to our customers in the Gatwick area and position British Airways as the number one European carrier to the Golden State.
“Boasting 260 days of sunshine, award-winning restaurants, some of the world’s best wine, a buzzing tech industry, great sports teams and world-renowned tourist attractions - there’s something for everyone.
“We are confident this route will be a big hit with British tourists.”