Port-de-Paix Airport (IATA: PAX) sits a couple of kilometres west of town on the coast road. It is small — a single strip and a basic terminal — but it is the practical way in if you want to avoid the long drive from Cap-Haïtien or Port-au-Prince. Sunrise Airways flies the short hop from Port-au-Prince when demand is there; schedules are unreliable, so check on the day.
The terminal is functional and nothing more. Taxis and shared motorcycles wait outside for the short ride into town or out to the boat jetty for Tortuga.