Long Branch is a borough in Washington County, Pennsylvania, United States.

[4] According to the United States Census Bureau, the borough has a total area of 3.3 square miles (8.5 km2), all land.

Long Branch has seven borders, including Twilight and Speers to the north, Dunlevy to the northeast, Allenport to the east and south, Elco to the southwest, California to the west, and Fallowfield Township in the northwestern corner.

At the 2000 census there were 539 people, 204 households, and 159 families living in the borough.

There were 216 housing units at an average density of 65.3 per square mile (25.2/km2).