The Baker Building, also known as Baker's Opera House, in Dover, Morris County, New Jersey, United States, is a historic theater built of brick in the mid-1880s. Built in the Eclectic style, it has three stories plus a tower. On the north side facing Blackwell Street, there are recessed brick panels, granite lintels and window sills, and a granite panel reading "Baker Building." A Mail Pouch Tobacco sign covers the south side of the building.