John Humphrey Noyes was an American preacher, radical religious philosopher, and utopian socialist. He founded the Putney, Oneida and Wallingford Communities, and is credited with coining the term "complex marriage".

Utopian socialism is the term often used to describe the first current of modern socialism and socialist thought as exemplified by the work of Henri de Saint-Simon, Charles Fourier, Étienne Cabet, and Robert Owen. Utopian socialism is often described as the presentation of visions and outlines for imaginary or futuristic ideal societies, with positive ideals being the main reason for moving society in such a direction. Later socialists and critics of utopian socialism viewed utopian socialism as not being grounded in actual material conditions of existing society. These visions of ideal societies competed with revolutionary and social democratic movements.