Condominium 1 was the first unit in the Sea Ranch development on the Pacific coast of Sonoma County, California.

The complex was designed by Charles W. Moore, Donlyn Lyndon, William Turnbull Jr. and Richard Whitaker of the MLTW partnership in 1963–1964, and was built by contractor Matthew Sylvia in 1965.

The design was inspired by barns and other farm buildings in the region and, with the help of landscape architect Lawrence Halprin, was built to take into account the local ecology.

It exemplifies Moore's "shed style" with single-pitched roofs, board siding, and plain detailing.

[2] The condominium was featured in an extensive public relations campaign to promote the Sea Ranch development and appeared in Newsweek, The New York Times, and Life, as well as design magazines such as Perspecta and Japan Architect.