Maj. Gen. William S. Harney Summer Home

Maj. Gen. William S. Harney Summer Home, also known as the Harney Mansion, is a historic home located at Sullivan, Crawford County, Missouri. It was built in 1856, and is a 1 3/4-story, eclectic dwelling constructed of native brown sandstone. The house has a rear wing added between 1869 and 1872. It was the summer home of William S. Harney, who purchased it in 1869.

Harney was known among the Sioux as "Woman Killer" due to his actions (known as the Harney Massacre) at an Indian village in 1855 at Blue Water Creek.

It is operated as a historic house museum.

It was listed on the National Register of Historic Places in 1984.