Michael Duane Johnson, (born September 13, 1967), is a U.S. former athlete, considered by many to be the greatest sprinter of all time. He holds world records for the 200m (19.32 s), 400m (43.18 s) and 4 x 400 relay (2:54.20, as part of the USA team). He won four Olympic gold medals and was a world champion nine times.

Johnson's achievements were rendered even more remarkable by his unique running style, with an upright stance and very short steps which defied the perceived wisdom that a high knee lift was essential for maximum speed.

Born in Dallas, Texas, he was the first man to win the 200 and 400 meters at the same Olympics, accomplishing the feat in 1996. (Two women have done the same: Valerie Brisco-Hooks in 1984 and Marie-José Perec in 1996.) A 1990 graduate of Baylor University, Johnson won a number of medals at the NCAA Indoor Track and Field Championships during his collegiate career.

The real breakthrough onto the world stage came in 1991 when Johnson won the World Championship 200m title in Tokyo. At the 1992 Summer Olympics Johnson failed to qualify to the 200m final, but won a gold as a member of the 4 x 400m relay team, which broke the world record (2:55.74).

After the disappointment of failing to make the final in his individual event at Barcelona, Johnson won 400m at the 1993 World Championships in Stuttgart. He won his second gold in the 4 x 400m relay race with a new world record (2:54.29).

In the next World Championships at Gothenburg Johnson did his first "double" in a major tournaments. He won both 200m and 400m and in addition to that got a gold again as a member of a relay team.

The next year Johnson finally broke the 200m world record when he ran 19.66 s at the USA National Championships. With that performance he qualified to run at the 1996 Olympic Games in Atlanta and prepared himself to attempt the "impossible" to win both titles — something no one had ever achieved. On July 29 he easily captured the 400m title in 43.49 s, beating Roger Black of Great Britain almost by second. At the 200m final on August 1, Johnson ran the opening 100 m in 10.12 s and finished the race in 19.32 s, a brilliant new world record. He reached a speed of 37 km/h.

This is the biggest improvement ever on a world 200m record. Most commentators could only find one comparable Olympic performance — Bob Beamon's 1968 long jump in Mexico.

In June of 1997 he raced against Canada's Donovan Bailey in a 150m race at Toronto's Roger's Centre, in a bid to truly determine who was the world's fastest man. Bailey won $1.5 million for winning that race, in which Michael Johnson pulled out of at the 100m with a pulled quadricep.

At the beginning of 1997 Johnson injured himself during a race over 150m with Donovan Bailey for a million dollars, but managed to win his third 400m World Champion title. In 1998 injury again struck in and his next season was troubled with two injury scares curtailing his 400m races to just four before the World Championships in Seville. Had it not been for the IAAF's policy of allowing defending champions automatic entry, he would not have been in Seville because he failed to compete in the USA trials when he was injured. But he recovered and won his fourth 400m World Champion title with a new world record of 43.18 s. He later ran the last leg of the 4 x 400m relay team to add a ninth World Championship gold medal to his collection.

Johnson ended his fabulous career at the 2000 Summer Olympics in Sydney by winning 400m and 4 x 400 relay race, thus bringing his total of Olympic golds to five. However, his gold medal count is likely to drop to four in the very near future.

In 2003, it was revealed that Jerome Young, who had run in preliminary rounds of the 4 x 400m relay, had been allowed to compete in Sydney despite a positive test for steroids in 1999. An appeals panel of USA Track & Field overruled the organization's doping expert, allowing Young to compete. The IAAF council has already voted to strip the relay team of its medal; the IOC was expected to follow suit before the opening of the 2004 Summer Olympics, but did not issue a final ruling as of September 2004.

Johnson has run 22 400-meter races under 44 seconds. In the 200m, he has six times under 19.80s and 17 sub-20 second performances. He also holds the world record at 300m — 30.85s. The former record was 31.48s.

Michael Johnson was perhaps the most eminent figure in athletics in the 1990s. For much of the decade he was virtually unbeaten in the long sprints. Since retiring from competitive sport, he has acted as a TV athletics pundit.