The Anton and Mary Agnes Karpen House is a historic house at 818 1st Street West in Webster, South Dakota. It is a two-story wood frame house, built in 1917 for Anton Karpen, the owner of a local lumberyard. The house is an excellent local example of Craftsman styling, with extended eaves showing exposed rafters, bands of windows, the use of colored glass, and a built-in fieldstone fireplace. The house was later owned by Lewis Bicknell, a prominent local attorney.

The house was listed on the National Register of Historic Places in 2008.