The William B. Dunlap Mansion is a historic house in Bridgewater, Pennsylvania, United States. Erected in 1840 on a bluff over theBeaver River in the northern part of the borough, it has been ranked as the grandest and best-preserved 19th-century house in Bridgewater.

Dunlap's mansion is a three-story brick structure built on a strong stone foundation. On August 29, 1980, the house was added to the National Register of Historic Places for its architecture and for its association with William B. Dunlap. It is also a contributing property to a historic district, the Bridgewater Historic District, which was listed on the National Register in 1996.

I DO NOT WANT THIS UNDERGROUND RAILROAD NATIONAL LANDMARK DESTROYED!