Octagon House, Historic residential building in Columbus, United States.

The Octagon House, also called May's Folly, stands at 527 1st Avenue in central Columbus, Georgia. It is a single-story wood-frame building with a front octagonal section under an octagonal roof topped by a cupola, its walls sheathed in clapboards, and a rear rectangular section. A Gothic Revival portico shelters the front entrance, and inside the octagonal part rooms form a Greek cross around a central chimney, with triangular closets and vestibules in the angled corners.

The older rear section was built about 1830 and served until 1852 as the home of Alfred Iverson, Sr., a United States senator. In 1863 the cabinetmaker Leander May bought the property and is credited with building the main octagonal structure, selling it in 1865. After passing through several owners, it became in 1967 the first acquisition of Historic Columbus and was declared a National Historic Landmark in 1973.

Locals call it May's Folly after Leander May, the cabinetmaker credited with building the main octagonal section in 1863. The older rear part, built about 1830, was home to U.S. Senator Alfred Iverson Sr. until 1852. In 1967 it became the first property acquired by Historic Columbus.

The house stands at 527 1st Avenue, on the west side between 5th and 6th Streets in central Columbus. It is a private residence, so the exterior is what visitors can see from the street; there is no public interior access. The front octagonal section faces 1st Avenue, with the older rectangular wing behind it.

The local historical society claims it is the only known double-octagon house in the United States: the rear section was originally octagonal too, and was probably made rectangular when the front octagon was added in 1863. The house is in private hands, so visitors see it from 1st Avenue.