The Southwest 737 was bound for San Jose but had not left the gate area when the smoke was observed.
The airline said flight 2123 was pushing back from the gate when the ground crew observed a possible fire near the rear exterior of the aircraft. The fire was in the aircraft's auxiliary power unit.
The emergency slides were deployed and the plane's 139 passengers and five crew members were all evacuated safely and the fire was extinguished.
The incident was first reported around 7:30 p.m.
A few minor injuries were reported, but none requiring a hospital transport.
Airline officials were working to get the passengers booked Monday night on other flights to San Jose.