Sorsogon, at the southeastern part of the Bicol Peninsula, is bounded on the north by the province of Albay, on the east by the Philippine Sea, on the south by the San Bernardino Strait, and on the west and northwest by the Ticao and Burias Passes. It has a total land area of 2,119 km2.

It is characterized by an irregular topography, and, except for landlocked Irosin, all the towns lie along the coast. They are all connected by concrete and asphalt roads. Mountains sprawl over the northeast, southeast and west portions. Mt. Bulusan, the tallest peak, rises 1,560 meters above sea level.

Except for its overland link with the province of Albay to the north, it is completely surrounded by water. Sorsogon is the gateway of Luzon to the Visayas and Mindanao through its roll-on, roll-off ferry terminal facilities located in the municipalities of Matnog and Bulan.