Self-sufficiency is the state of not requiring any aid, support, or interaction, for survival; it is therefore a type of personal or collective autonomy. On a national scale, a totally self-sufficient economy that does not trade with the outside world is called an autarky.

The term self-sufficiency is usually applied to varieties of sustainable living in which nothing is consumed outside of what is produced by the self-sufficient individuals. Examples of attempts at self-sufficiency in North America include simple living, homesteading, off-the-grid, survivalism, DIY ethic and the back-to-the-land movement.

Practices that enable or aid self-sufficiency include autonomous building, permaculture, sustainable agriculture, and renewable energy.

The term is also applied to limited forms of self-sufficiency, for example growing one's own food or becoming economically independent of state subsidies.

Eustace Conway (born Eustace Robinson Conway IV in 1961 in South Carolina) is an American naturalist and the subject of the book The Last American Man by Elizabeth Gilbert and the subject of an early episode of the weekly radio show This American Life. He is the owner of 1,000-acre (4.0 km²) Turtle Island Preserve near Boone, North Carolina.

At the age of 12, Conway lived in the woods for a week. At 17 he moved out of his parents' home entirely so that he could live in a teepee in the woods. He has hiked the entire Appalachian Trail and claims to have set the world record for crossing the United States on horseback from the Atlantic to the Pacific. However, according to the New York Times and Los Angeles Times of the day, as well as the book, Bud & Me, the record for crossing the North American continent on horseback was actually done in 62 days. This journey was made by Bud and Temple Abernathy, aged 11 and 7, who rode 3,619 miles (5,824 km) from New York to San Francisco on an equestrian journey, which started in August, 1911.