Mount Vernon Mill No. 1 is a historic cotton mill complex located at Baltimore, Maryland, United States. It was constructed between 1873 and 1918 and consists of four buildings situated along Jones Falls. The complex consists of three closely associated 19th century buildings and a 20th-century warehouse. There is a large, three-story brick Mill Building (1873); a two-story, brick, "L"-shaped Picker House (1873); a two-story, brick Store House (c. 1881); and a later, reinforced-concrete warehouse (1918). It served as headquarters for Mount Vernon-Woodberry Mills, one of the world's largest producers of cotton duck.