Fossett grew up in California, where he studied economics and philosophy at Stanford University (B.A., 1966). After earning an M.B.A. (1968) at Washington University in St. Louis, Mo., he became a successful commodities broker, and in 1980 he founded the securities company Lakota Trading. Fossett undertook a number of challenges, including swimming the English Channel (1985), before gaining international attention with his ballooning feats. In 1995 he registered his first record in the sport with a solo transpacific flight. The following year he began his highly publicized effort to become the first person to balloon around the world alone. The initial attempt, however, ended after three days, and a series of subsequent efforts also failed. In 2002 Fossett made his sixth attempt at the record, taking off from Northam, West Australia, in the Spirit of Freedom. On July 2 he made history as he crossed his starting point, eventually landing in the outback of Queensland.

In 2005 Fossett became the first person to fly an airplane around the world solo without stopping or refueling. Piloting the GlobalFlyer, a specialized plane that featured 13 fuel tanks and a 7-foot (2-metre) cockpit, he took off from Salinas, Kansas, on February 28 and returned there some 67 hours later, on March 3. On Feb. 8, 2006, he undertook the longest nonstop airplane flight, taking off from Cape Canaveral, Florida, aboard the GlobalFlyer. Some 76 hours later, on February 11, he made an emergency landing in Bournemouth, England, having covered a record 26,389.3 miles (42,469.5 km).

Fossett was also renowned as a speed sailor. In 2001 he recorded the quickest transatlantic crossing—4 days 17 hr 28 min 6 sec—and in 2004 he circumnavigated the globe in an unprecedented time of 58 days 9 hr 32 min 45 sec. By the early 21st century, he had set some 100 records in sailing and aviation. His other achievements included the fastest flight (742.02 miles per hour 【1,194.17 km per hour】) in a nonsupersonic airplane (2001) as well as a number of gliding records.

On Sept. 3, 2007, Fossett was reported missing after his single-engine plane disappeared during a scouting mission in western Nevada. Subsequent search efforts were hampered by the area's remoteness and rugged terrain. On Feb. 15, 2008, Fossett was declared dead by a court in Chicago. In October the wreckage of his plane and what were believed to be his remains were found in Inyo National Forest, Nevada; DNA tests later confirmed that the bones belonged to Fossett.