Do you know What Terminal is Frontier at sfo At San Francisco International Airport (SFO), Terminal 1 is where Frontier Airlines is based. Domestic and international flights are served by Terminal 1, sometimes referred to as the Harvey Milk Terminal. This terminal houses check-in desks, security screening, baggage claim, and a variety of services for passengers flying with Frontier Airlines. For the comfort and convenience of travellers, it provides a variety of food establishments, retail outlets, and amenities. Closer to your departure date, it is advised to confirm the terminal information with Frontier Airlines or SFO, since operational needs may result in changes to terminal designations.