The Waddel Mansion is a historic house at 605 West 5th Street in Webster, South Dakota.

Built in 1920 by William Waddel, a local lawyer, it was then, and still is, the largest house in the small community.

The house has a symmetrical main block, with matching recessed wings on either side.

The roof has Craftsman style deep eaves supported by large curving brackets, a detail repeated on dormers and projecting sections.

This article about a property in South Dakota on the National Register of Historic Places is a stub.