Haines Mill, also known as Haines Mill Museum, is a historic grist mill located at South Whitehall Township, Lehigh County, Pennsylvania. It was built about 1840, and is a four-story, stone building with a slate covered gambrel roof. It is three bay by three bay, 42 feet by 46 feet, 9 inches. The interior was rebuilt after a disastrous fire in 1908. A three-story brick addition was built in 1930, with a lean-to roof. Atop the main roof is a cupola. It remained in full operation until 1957. Today, Haines Mill is operated as a partnership between the County of Lehigh, which owns and maintains the site, and the Lehigh County Historical Society, which provides public tours.