By Plane:
Philip S. W. Goldson International Airport (BZE) is the largest airport in the country and is undergoing an expansion that should be completed by 2015. Once the expansion is completed the airport should be able to handle direct flights from Europe. Due to the number of tourist flying in and out of this airport there are several airlines that have direct flights to quite a few cities in North America and Central America.

Aero Caribbean - Havana
American Airlines - Dallas/Fort Worth and Miami
Continental Airlines - Houston and New York (Newark)
Delta Airlines - Atlanta
Maya Island Air - Cancun, Caye Caulker, Caye Chapel, Corozal, Dangriga, Guatemala City, San Pedro Sula, Placencia, Punta Gorda and, Savanah and Ambergris Caye
Pinnacle Airlines - Atlanta
TACA - San Salvador
Tropic Air - Belmopan, Caye Caulker, Coroza, Dangriga, Flores, Kanantik, Placencia, Punta Gorda, Ambergris Caye and Sarteneja
US Airways - Charlotte
Philip S. W. Goldson is about 30 minutes drive from Belize City's centre, in Ladyville. The best way to get to and from the city centre is via taxi. Although an airport bus service exists, it is very infrequent and unreliable.

By Car:
The best routes into the country are from Chetumal in Mexico to cross into the north of Belize, or in the west from Flores in Guatemala. You need to buy a permit and insurance to bring your car into Belize and you need to be the owner of the car.

By Bus:
There are three official border crossings into Belize, two from Mexico and one from Guatemala (in the west). From both directions there are frequent direct services from Flores in Guatemala and Chetumal in Mexico to Belize City and several other places on the route, like San Ignacio.

By Boat:
There are several connections from towns in the south of Belize like Dangriga and Punta Gorda to places in neighbouring Honduras and Guatemala, like Puerto Cortes (Honduras) and Puerto Barrios and Livingston (Guatemala). Services to Livingston are usually twice week, while Puerto Barrios is served on a daily basis.

There is also a connection between Placencia (via Big Creek) to Puerto Cortes but it doesn't go very often, usually once a week. If you are going to/from Honduras you can take a "water taxi" here's the ferry website.

To Belize (Big Creek & Placencia), Departure: Puerto Cortez - Every Monday at 11:30am (Leaves from "Puente Laguna" (Lagoon Bridge) next to Delfin Restaurant in Puerto Cortes)
To Honduras (Puerto Cortez), Departure: Placencia - Every Friday at 9:30am (Leaves from Placencia Shell Dock), Departure: Big Creek - Every Friday at 11:00am.