The Frederick Weistar House is a historic house at 515 Chestnut Street in Chester, Illinois. The house was built circa 1859 for Frederick Weistar, a Swiss immigrant. The house has a vernacular design with a two-door facade pattern, in which two front doors provided access to each of the house's two first-floor rooms. While the two-door facade is common in vernacular architecture, the purpose of the two doors is historically disputed; as the form is especially prevalent in German vernacular architecture, it may have been inspired by traditional German architecture, though it may have also functioned as a way to separate public and private spaces in a home. The one-story limestone house also features a wooden front porch with carved columns and brackets, its only significant decorative element.The house was added to the National Register of Historic Places on June 15, 2018; its name was misspelled "Frederick Weister House" in its listing.