Longfellow-Hastings House, Historic residence in Pasadena, United States.

The Longfellow–Hastings House, also called the Octagon House, is a two-story octagon house built in 1893 by Gilbert Longfellow, who had earlier built a similar house on the Atlantic coast. It has a frieze and a dentilated cornice, and a verandah originally surrounded it. It is one of the few octagon houses remaining in the Western United States and now stands at the Heritage Square Museum.

Gilbert Longfellow built the house in 1893 at 85 South Allen Avenue in Pasadena, after having built a similar octagon house on the Atlantic coast. It was added to the National Register of Historic Places on March 2, 1982, and since the mid-1980s it has stood at the Heritage Square Museum.

The house is called the Octagon House for its eight-sided plan, one of the few octagon houses left in the Western United States. It now stands at the Heritage Square Museum, where it has been since the mid-1980s, rather than at its original Allen Avenue address.

The house no longer stands at 85 South Allen Avenue in Pasadena; it was moved to the Heritage Square Museum in the mid-1980s, where it remains. Check the museum's opening arrangements before travelling, since access to the moved buildings depends on its operating days. The octagonal form, frieze and dentilated cornice can be picked out from the museum grounds.

The house was moved from 85 South Allen Avenue in Pasadena to the Heritage Square Museum in the mid-1980s, so its present setting is not its original one. It is among the few octagon houses left in the Western United States, and it joined the National Register of Historic Places on March 2, 1982.