Southwest Airlines has become the dominant carrier across Southern California through decades of measured expansion, with its strongest position concentrated at the region’s secondary airports rather than the largest hubs. The airline’s network now gives it more than 27% of scheduled departures across California, well ahead of Alaska Airlines, while its hold on Long Beach remains especially deep.
Southwest entered Southern California on 31 January 1982 with service to San Diego, then added Los Angeles that September with links to Phoenix and Las Vegas. Ontario followed in 1985, and the carrier kept building airport by airport, steadily turning regional scale into a commercial advantage. Legacy low-fare operators such as PSA and AirCal helped shape the market before disappearing, but Southwest’s disciplined growth outlasted them.
That approach left Southwest short of dominance at the state’s biggest airports, yet it became the clear leader at secondary fields where capacity is limited and market share is easier to lock in over time. At Long Beach, where a strict slot regime governs service levels, the airline holds roughly 86% of commercial slots, underlining how thoroughly it has embedded itself in Southern California’s constrained airport network.