Union Mills is an historic textile mill complex located on Pleasant Street in Fall River, Massachusetts.
The Union Mills company was incorporated in 1859, and was the first large steam-powered mill built in the city, having installed Corliss steam engines. The buildings are constructed from native Fall River granite. The company's first president was S. Angier Chace, and David Anthony was the first treasurer. It was the first mill corporation established in the city on the basis of general subscriptions.
In 1865, Mill No. 2 was constructed. In 1876 the original gable roofs of both mills were removed and replaced with flat roofs, thereby adding additional floor space. A third mill was later constructed adjacent to Mill No. 2, but was demolished in the 1960s for the construction of Interstate 195. Production of textiles ceased in 1929.
In 1968 the site was photographed by Jack E. Boucher of the Historic American Buildings Survey, along with the adjacent Durfee Mills. The site was added to the National Historic Register in 1983.
Mill No.1 is currently occupied by numerous small businesses, including Nate Lions Appliance Warehouse for many years before it move to the nearby Durfee Mills. Mill No.2 has been completely restored and is now the location of Prima CARE Medical Center