You’ll be finding plenty of cheap international flights from San Francisco to Paris operated by world-class carriers. When you are flying out from San Francisco to Paris your departing airport will be San Francisco International Airport (IATA code: SFO) in San Francisco and your arrival airport will be Charles de Gaulle Airport (IATA code CDG) in Paris. You can fly non-stop or with a layover / stopover option across SFO to CDG depending on your convenience and budget. A connecting flight with a layover may sometimes work out cheaper but you may have to compromise on the long hours of travel time.