Diego Aracena International Airport (IQQ) is 40 kilometres south of the city. LATAM, JetSmart, and SKY fly multiple times a day from Santiago (roughly two hours twenty minutes). There are also occasional international flights to and from La Paz in Bolivia and Asunción in Paraguay.
Buses are an alternative if you have time. The Pan-American Highway runs along the coast, and overnight buses connect Iquique with Antofagasta, Calama, La Serena, and Santiago. The Santiago bus is around 24 hours; Antofagasta is six. From Arica it is around four hours; from the Bolivian border at Colchane, around five.
A shared taxi from the airport into town costs around CLP 8,000; a private cab is around CLP 20,000. There is no rail service.