Triadelphia is a town in Ohio County, West Virginia, United States.

It is part of the Wheeling, West Virginia Metropolitan Statistical Area.

[6] It is home to the Highlands, the largest retail complex in the Northern Panhandle of West Virginia.

Located near Triadelphia is the David Stewart Farm, listed on the National Register of Historic Places in 1979.

[9] According to the United States Census Bureau, the town has a total area of 0.67 square miles (1.74 km2), all land.

34.0% of all households were made up of individuals, and 8.8% had someone living alone who was 65 years of age or older.

25.9% were of German, 13.4% Irish, 11.2% Italian, 9.3% Polish, 8.9% American and 7.0% English ancestry according to Census 2000.

U.S. Route 40 (US 40) runs through the northeastern suburbs of Wheeling, Triadelphia and Valley Grove.