The Market Square Historic District of Houlton, Maine encompasses that town's historic late-19th century central business district. Centered on the junction of Market Square, Court Street, Water Street, and Main Street, it includes a relatively cohesive assortment of brick and masonry commercial buildings, designed by architects and built between 1885 and 1910, following the arrival of the Bangor and Aroostook Railroad. The district was listed on the National Register of Historic Places in 1980.