The 100 metres, or 100-metre dash, is a sprint race in track and field competitions. The shortest common outdoor running distance, it is one of the most popular and prestigious events in the sport of athletics. It has been contested at the Summer Olympics since 1896 (1928 for women). The reigning 100 m Olympic champion is often named "the fastest man/woman in the world".

On an outdoor 400 metres running track, the 100 m is run on the home straight, with the start sometimes being set on an extension to make it a straight-line race. Runners begin in the starting blocks and the race begins when an official fires the starter's pistol. Sprinters typically reach top speed after somewhere between 50–60 m. Their speed then slows progressively towards the finish line.

The 10-second barrier has historically been a barometer of fast men's performances, while the best female sprinters take eleven seconds or less to complete the race. The current men's world record is 9.58 seconds, set by Jamaica's Usain Bolt while American Florence Griffith-Joyner holds the women's world record of 10.49 seconds.

Asafa Powell CD (born 23 November 1982) is a Jamaican sprinter who specialises in the 100 metres. He held the 100 m world record between June 2005 and May 2008, with times of 9.77 and 9.74 seconds respectively. Powell has consistently broken the 10-second barrier in competition, with his personal best of 9.72 s being the fourth fastest time in the history of the event. As of 2nd May 2012, Powell has broken the ten-second barrier legally more times than anyone else – 74 times in total.

Powell competed in the 100 m at the 2004 Athens Olympics and the 2008 Beijing Olympics but failed to convert his success to the world stage, finishing fifth both times. However, in Beijing with the Jamaican team he won a gold medal and set the world and Olympic record in the 4 × 100 metres relay. At the 2007 Osaka World Championships he won a bronze and a silver medal in the 100 m and 4 x 100 m relay respectively and he has been successful at the Commonwealth Games, winning two gold and one silver medal. At the 2009 World Championships he won 100 m bronze and a relay gold. Powell has won five times at the IAAF World Athletics Final and is the 100 m record holder for the event.

The Honourable Usain St. Leo Bolt, OJ, C.D. ( /ˈjuːseɪn/; born 21 August 1986), is a Jamaican sprinter and a five-time World and three-time Olympic gold medalist. He is the world record and Olympic record holder in the 100 metres, the 200 metres and (along with his teammates) the 4×100 metres relay. He is the reigning Olympic champion in these three events, and is one of only seven athletes (along with Valerie Adams, Veronica Campbell-Brown, Jacques Freitag, Yelena Isinbayeva, Jana Pittman, Dani Samuels) to win world championships at the youth, junior, and senior level of an athletic event.

Bolt won a 200 m gold medal at the 2002 World Junior Championships, making him the competition's youngest-ever gold medalist at the time (since surpassed by Jacko Gill). In 2004, at the CARIFTA Games, he became the first junior sprinter to run the 200 m in less than 20 seconds with a time of 19.93 s, breaking the previous world junior record held by Roy Martin by two-tenths of a second. He turned professional in 2004, and although he competed at the 2004 Summer Olympics, he missed most of the next two seasons due to injuries. In 2007, he broke Don Quarrie's 200 m Jamaican record with a run of 19.75 s.