Cole County Historical Society Building, also known as the B. Gratz Brown House, is a historic building located at Jefferson City, Cole County, Missouri. It was built in 1871, and is a two-story, Victorian style, brick rowhouse. It is three bays wide and features segmental arched windows. It was renovated in 1948. It was listed on the National Register of Historic Places in 1969. It is located in the Missouri State Capitol Historic District.