Middlebourne is a town in Tyler County, West Virginia, USA. The population was 870 at the 2000 census. It is the county seat and was established by an enactment of the Virginia General Assembly in 1813. Two explanations have been given for the name of the town: One is that it was located halfway between Pennsylvania and a series of salt wells along the Kanawha River upstream of Charleston; the other is that it is located midway between the source and the mouth of Middle Island Creek, which flows through the town.
Middlebourne is located at 39°29′38″N 80°54′21″W / 39.49389°N 80.90583°W / 39.49389; -80.90583 (39.493966, -80.905751).
According to the United States Census Bureau, the town has a total area of 0.4 square miles (1.0 km²), all land.