The first world record in the 400 m for men (athletics) was recognized by the International Amateur Athletics Federation, now known as the International Association of Athletics Federations, in 1912. The IAAF ratified Charles Reidpath's 48.2 performance set at that year's Stockholm Olympics as a world record, but it also recognized the superior mark over 440 yards (402.34 metres) run by Maxie Long in 1900 as a world record.
To June 21, 2009, the IAAF has ratified 23 world records in the event.
The following tables show the world record progression in the men's 400 metres, as ratified by the IAAF.
(+) plus sign denotes en route time during longer race
"y" denotes time for 440 yards, ratified as a record for this event
"A" indicates that the time was set at altitude.
The "Time" column indicates the ratified mark; the "Auto" column indicates a fully automatic time that was also recorded in the event when hand-timed marks were used for official records, or which was the basis for the official mark, rounded to the 10th or 100th of a second, depending on the rules then in place.
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.
Lee Evans' 1968 Olympic gold medal victory time of 43.86 was the fastest recorded result to that time.
|Time||Athlete||Nationality||Location of race||Date|
|43.86A||Lee Evans||United States||Mexico City, Mexico||October 18, 1968|
|43.29||Butch Reynolds||United States||Zürich, Switzerland||August 17, 1988|
|43.18||Michael Johnson||United States||Seville, Spain||August 26, 1999|
|43.03||Wayde van Niekerk||South Africa||Rio de Janeiro, Brazil||August 14, 2016|
- "12th IAAF World Championships In Athletics: IAAF Statistics Handbook. Berlin 2009" (PDF). Monte Carlo: IAAF Media & Public Relations Department. 2009. pp. Pages 546, 547. Archived from the original (pdf) on June 29, 2011. Retrieved August 2, 2009.
- "The Official Report of the Games of the 8th Olympiade" (PDF). Paris, FR. 1924. p. 107. Retrieved 21 April 2011.
- Hymans, Richard; Matrahazi, Imre. "IAAF World Records Progression" (pdf) (2015 ed.). International Association of Athletics Federations. Retrieved April 30, 2018.
- "Men's 400m Results" (PDF). Rio 2016. International Olympic Committee. 14 August 2016. Archived from the original (PDF) on 20 September 2016. Retrieved 3 September 2016.
- Eric Lidell's 1924 Olympic Games victory was initially ratified as a world record by the IAAF, despite being slower than Ted Meredith's mark from 1916. The IAAF rescinded the record on August 7, 1928.