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.

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.

Yohan Blake (born December 26, 1989) is a Jamaican sprinter and the current 100 metre World Champion. He holds the national junior record for the 100 metres, and is the youngest sprinter to have broken the 10-second barrier (at 19 years, 196 days). Blake's personal best of 9.82 seconds makes him the fourth fastest Jamaican runner, after Nesta Carter, Asafa Powell and Usain Bolt. His fastest run under any conditions is 9.80 seconds in May 2011 in Kingston, but the wind assistance (+2.2 m/s) was over the legal limit. He is coached by Glen Mills, and is training partners with Bolt and Daniel Bailey. On September 16, 2011 in Brussels, Belgium, he won in a time of 19.26 seconds, the second fastest 200 m ever.

Born in St. James, Jamaica, Blake is the son of Veda and Shirley Blake. He attended St. Jago High School in Spanish Town.

Blake set the fastest time by a Jamaican junior sprinter over 100 m with 10.11 seconds. The record was set at the 2007 CARIFTA Games held in the Turks and Caicos islands where he also led his team to gold in the 4 × 100 metres relay. At this occasion, he was awarded the Austin Sealy Trophy for the most outstanding athlete of the 2007 CARIFTA Games.

Justin Gatlin (born February 10, 1982) is an American sprinter. He is an Olympic gold medalist, with a 100 m personal best of 9.85 seconds and two-time World indoor champion in the 60-meter dash. He served a four-year ban from track and field for testing positive for a banned substance; Gatlin had appealed the ban in 2009, but it was later denied.

Gatlin attended Woodham High School in Pensacola, Florida.

In the fall of 2000, Gatlin arrived at University of Tennessee, Knoxville, as a good high school 110 m hurdler. During high school, Justin was recruited for track by coaches Vince Anderson and Bill Webb who quickly realized his potential and turned him into a sprinter. After training and competing in UT's program for two years under the guidance of former Tennessee assistant Vince Anderson, Gatlin won six consecutive NCAA titles. In the fall of 2002, Gatlin left Tennessee after his sophomore season to join the professional ranks. Just two years later, he won the gold medal in the 100 m (9.85 s) at the 2004 Summer Olympics, narrowly beating Francis Obikwelu of Portugal and the defending champion Maurice Greene. He also won a bronze medal in a USA sweep of the 200 m race, and a silver medal as a member of the 4 x 100 m relay squad. In the 2005 World Athletics Championships in Helsinki, he again triumphed over 2003 champion Kim Collins, capturing the gold medal in the 100 m.

Tyson Gay (born August 9, 1982) is an American track and field sprinter. His primary events are the 100 meters and 200 meters. His personal bests establish him as the second fastest athlete in the 100 meters and the fifth fastest athlete in the history of the 200 meters, with times of 9.69 (which is a United States record) and 19.58 seconds respectively.

Gay has won numerous medals in major international competitions, including a gold medal sweep of the 100 m, 200 m and 4 x 100 meters relay at the 2007 Osaka World Championships. This made Gay the second sprinter to win all three events at the same World Championships, after Maurice Greene.

At the same meet, Gay suffered a severe hamstring injury in the 200 m event. The injury persisted and this contributed to his failure to win a single medal at the Beijing Olympics. As a participant in the US Anti-Doping Agency's "Project Believe" program, Gay is regularly tested to ensure that his system is clean of performance-enhancing drugs.

Gay also holds the record for the fastest non-winning time for the 100 meters. In August 2009, he ran 9.71 seconds in the World Athletics Championships from Berlin, Germany. Tyson Gay remains the only sprinter to have defeated Usain Bolt in a final since Bolt made his first world record run. Gay ran a wind assisted 9.68 at the 2008 US Olympic trials.