There are three main options in getting to Placencia from the Belize International airport
You can rent an automobile or take a private charter from the Philip Goldson International Airport to Placencia. This is a 3.5 hour drive.
You can also take local bus from Belize City to Placencia whichis about a 5 hour ride (not recommended).
A faster option is flying to Placencia from the Philip Goldson International Airport on a local airline. The flight is only about 45 minutes long and the cost is approx. US$158 for a round trip ticket or US$90 for a one way ticket.