Men's 100 metres world record

The first record in the 100 metres for men (athletics) was recognised by the International Amateur Athletics Federation, now known as the International Association of Athletics Federations, in 1912. The record now is 9.58 seconds which was run by Usain Bolt.

As of 21 June 2011^[update], the IAAF had ratified 67 records in the event, not including rescinded records.

The first manual time of 9.9 seconds was recorded for Bob Hayes in the final of the 100 metres at the 1964 Olympics. Hayes' official time of 10.0 seconds was determined from the electronic time of 10.06 and rounding down to the nearest tenth of a second to give the appearance of a manual time. This method was unique to the Olympics of 1964 and 1968. The officials at the track recorded Hayes' time as 9.9 seconds.

From 1975, the IAAF accepted separate automatically electronically timed records for events up to 400 metres. Starting January 1, 1977, the IAAF required fully automatic timing to the hundredth of a second for these events.

Jim Hines' October 1968 Olympic gold medal run was the fastest recorded fully electronic 100 metre race to that time, at 9.95.Track and Field News has compiled an unofficial list of automatically timed records starting with the 1964 Olympics and Bob Hayes' gold medal performance there. Those marks are included in the progression.

The IAAF considers marks set at high altitude as acceptable for record consideration. However, high altitude can significantly assist sprint performances. One estimate suggests times in the 200m sprint can be assisted by between 0.09 s and 0.14 s with the maximum allowable tailing wind of (2.0 m/s), and gain 0.3 s at altitudes over 2000 m. For this reason, unofficial low-altitude record lists have been compiled.

After the IAAF started to recognise only electronic times in 1977, the then-current record and subsequent record were both set at altitude. It was not until 1987 that the world record was equalled or surpassed by a low-altitude performance. The following progression of low-altitude records therefore starts with Hines's low-altitude "record" when the IAAF started to recognise only electronic timing in 1977, and continues to Lewis's low-altitude performance that equalled the high-altitude world record in 1987. (Ben Johnson's 9.95 run in 1986 and 9.83 run in 1987 are omitted.)

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