The 100 metres at the World Championships in Athletics has been contested by both men and women since the inaugural edition in 1983. It is the second most prestigious 100 m title after the 100 metres at the Olympics. The competition format typically has two or three qualifying rounds leading to a final between eight athletes. Since 2011 a preliminary round has been held, where athletes who have not achieved the qualifying standard time compete to enter the first round proper.
The championship records for the event are 9.58 seconds for men, set by Usain Bolt in 2009, and 10.70 seconds for women, set by Marion Jones in 1999. The men's world record has been broken or equalled at the competition three times: by Carl Lewis in 1987 and 1991, and by Usain Bolt in 2009.Ben Johnson ran faster than Lewis in 1987, but his record was subsequently annulled due to doping. Lewis's mark, which equalled the standing record at the time, was never officially ratified by the IAAF as a world record. The women's world record has never been beaten at the championships.
The United States is the most successful nation in the discipline, having won fifteen gold medals. Jamaica are a clear second with six gold medals. East Germany, with two, is the only other nation to have won multiple titles.
Tim Montgomery became the 100 m second medalist to be disqualified, losing his silver medal from the 2001 World Championships in Athletics. From the same event, Marion Jones later lost her silver medal for doping infractions, becoming the first female medalist to be stripped of a 100 m medal. Venolyn Clarke and Kelli White (a women's finalist) were also disqualified that year. The results of Dwain Chambers and Mongomery, fourth and fifth in 2003, were removed for doping. Two women's medalists were stripped of their honours for doping Kelli White lost the world title while Zhanna Block had her bronze medal removed. Block's times from the 2005 edition were also annulled. These disqualifications were a result of the BALCO scandal, which included many 100 m runners.
Among the men's world champions, only Donovan Bailey and Usain Bolt have not been implicated in doping during their careers. Three-time champion Maurice Greene never failed a drug test, but admitting purchasing drugs on other athletes behalf.