Historically, societies who have advocated multiple sexual partners are not uncommon. For example, royalty and nobility in several cultures had both consorts and concubines. Notably, ancient Roman culture is popularly believed to have enthusiastically accepted of orgies and alternative sexual practices.[citation needed] Nevertheless, though contemporary swingers may celebrate these historical ideals, the actual practice of swinging in the 20th century began differently.

According to Terry Gould's The Lifestyle: A Look at the Erotic Rites of Swingers [2], swinging began among United States Air Force pilots and their wives during World War II. In this small community, the mortality rate among pilots was significantly high. Gould reports that a close bond between pilots arose, with the implication that the husbands would protect and care for all the wives as their own, both emotionally and sexually, if the husbands were away or lost (thus bearing some similarity to levirate marriage).

This historical narrative is debatable, however, since it would have been highly unusual for military wives to accompany their husbands on foreign tours of duty. Other sources point to U.S. Air Force pilots stationed in the California desert as the original participants in modern swinging. Though the exact beginnings are not agreed upon, it is widely assumed that swinging began amongst American military communities in the 1950s.

By the time the Korean War ended, the practice of swinging had spread from the military bases to the nearby suburbs. The media promptly dubbed the phenomenon wife-swapping.

The first swingers' organization, the Sexual Freedom League, began in the 1960s in Berkeley, California, in the sexually liberal San Francisco Bay Area. Ultimately, an umbrella organization called the North American Swing Club Association (NASCA)[3] (now NASCA International) was formed to encourage the dissemination of accurate information about swinging lifestyles across North America.

In the United Kingdom there was a proliferation of neighbourhood swingers groups in the early 1970s (at that time these were generally known as "wife swapping" groups). In various press articles written in later years it appears that the peak of this activity was 1973-75.