Đông Hà is situated at the crossroads of National Highway 1A and Route 9, part of the East–West Economic Corridor (EWEC).

EWEC is an economic development program which includes northeast Thailand, Southern Laos, and central Vietnam.

The city was initially part of Champa, until it was conquered by the Qin Empire who were in control of most of Vietnam at the time.

During the Vietnam War, Đông Hà was the northernmost town in South Vietnam and was the location of a strategically important United States Marine Corps Đông Hà Combat Base, to support Marine positions along the Vietnamese Demilitarized Zone (DMZ).

There is a wet season due to the northeast monsoon between August and December, peaking in October with around 629.7 millimetres or 25 inches of rain and frequent typhoon landfalls.