The best price found from United States to San Andrés is on September 6th, 2019, travelling with Spirit Airlines. See more options, compare prices and book: search flights.
Gustavo Rojas Pinilla International Airport is right in the town center and the runway ends at the beach. You must buy a tourist card (COP$105,000) on the mainland before boarding your San Andrés–bound flight, but the cards are sold at the gate and there's no chance you'll be allowed to board without one. Airlines that connect to San Andrés include Avianca, LATAM and Copa, and cities with direct flights here include Bogotá, Barranquilla, Cali, Cartagena, Medellín and Panama City.
Satena operates two flights per day between San Andrés and Providencia in low season (round trip from COP$600,000) and up to six per day in high season.
The airport is a 10-minute walk from the town center, or a flat-fare COP$15,000/7000 ride by taxi/moto-taxi. If you don't have much luggage, it's an easy walk. There's a left-luggage room at the airport (COP$5000 per item per 24 hours).