Orion Clemens House, Historic residence in Carson City, United States.

The Orion Clemens House is a two-story Late Victorian house at 502 N. Division St. in Carson City, Nevada. It was built in 1862 by Orion Clemens, the first Secretary of the Nevada Territory, and is also known as Mark Twain's House. The National Register listing includes two contributing buildings.

Orion Clemens, a lawyer and the first Secretary of the Nevada Territory, built the house in 1862. It was known as the Governor's Mansion when he served as territorial governor pro tem while Governor James W. Nye was absent. The property was listed on the National Register of Historic Places in 1979, and the listing included two contributing buildings.

The house is also called Mark Twain's House because Orion's younger brother Samuel Clemens, later Mark Twain, often stayed here. Orion, a lawyer and the first Secretary of the Nevada Territory, built it in 1862; when Governor James W. Nye was away, Orion served as acting governor and the house was known as the Governor's Mansion.

The house stands at 502 N. Division St. in Carson City, north of the downtown historic district, and is a stop on the Kit Carson Trail walking route marked by historic plaques. It is a private two-story building, so visitors see the exterior from the street; the property includes two contributing buildings.

The property gained recognition on the National Register of Historic Places in 1979, which formally acknowledged its importance to the early history of Nevada. This designation included two buildings on the grounds.