The best price found from United States to Havana is on September 18th, 2017, travelling with United. See more options, compare prices and book: search flights.
Aeropuerto Internacional José Martí is at Rancho Boyeros, 25km southwest of Havana via Av de la Independencia. There are four terminals here. Terminal 1, on the southeastern side of the runway, handles only domestic Cubana flights. Terminal 2 is 3km away via Av de la Independencia and receives flights and charters from the US. All other international flights use Terminal 3, a well-ordered, modern facility at Wajay, 2.5km west of Terminal 2. Charter flights, mainly to Cuban destinations, are from the Caribbean Terminal (also known as Terminal 5) at the northwestern end of the runway, 2.5km west of Terminal 3. Terminal 4 handles freight. Check carefully which terminal you'll be using.
Aerogaviota is a Cuban airline run by the government tourist agency that handles mainly domestic flights to places like Holguín and Cayo Coco.
Public transportation from the airport into central Havana is practically nonexistent. A standard taxi will cost you approximately CUC$20 to CUC$25 (30 to 40 minutes).
True adventurers with light luggage and a tight budget can chance their arm on the P-12 metro bus from the Capitolio or the P-15 from the Hospital Nacional Hermanos Ameijeiras on the Malecón, both of which go to Santiago de las Vegas, stopping close to the airport (about 1.5km away) on Av Boyeros. This is a lot easier for departing travelers, who will have better knowledge of local geography.