Topographical features divide the Belizean landscape into two main physiographic regions. The most visually striking of these regions is distinguished by the Maya Mountains and the associated basins and plateaus that dominate all but the narrow coastal plain in the southern half of the country. The mountains rise to heights of about 1,100 meters, with the highest point being Victoria Peak (1,120 meters) in the Cockscomb Mountains. Covered with shallow, highly erodible soils of low fertility, these heavily forested highlands are very sparsely inhabited.

The second region comprises the northern lowlands, along with the southern coastal plain. Eighteen major rivers and many perennial streams drain these low-lying areas. The coastline is flat and swampy, with many lagoons, especially in the northern and central parts of the country. Westward from the northern coastal areas, the terrain changes from mangrove swamp to tropical pine savannah and hardwood forest.

The interlocking networks of rivers, creeks, and lagoons have played a key role in the historical geography of Belize. The largest and most historically important river is the Belize, which drains more than one-quarter of the country as it winds along the northern edge of the Maya Mountains across the center of the country to the sea near Belize City. Also known as the Old River, the Belize River is navigable up to the Guatemalan border and served as the main artery of commerce and communication between the interior and the coast until well into the twentieth century. Other historically important rivers include the Sibun, which drains the northeastern edge of the Maya Mountains, and the New River, which flows through the northern sugar-growing areas before emptying into Chetumal Bay. Both of these river valleys possess fertile alluvial soils and have supported considerable cultivation and human settlement.