Sunnyside, also known as the Townsend Mikell House, is a historic plantation house located at Edisto Island, Charleston County, South Carolina. The main house was built about 1875, and is a 1+1⁄2-story, rectangular, frame, weatherboard-clad residence. It features a mansard roof topped by a cupola and one-story, hipped roof wraparound porch. Also on the property are the tabby foundation of a cotton gin; two small, rectangular, one-story, gable roof, weatherboard-clad outbuildings; a 1+1⁄2-story barn; and the Sunnyside Plantation Foreman's House. The Foreman's House is a two-story, weatherboard-clad, frame residence built about 1867.

It was listed on the National Register of Historic Places in 1986, with a boundary increase in 1994.