Men's 400 metres world record progression
The first world record in the 400 m for men 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 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.
Records 1912–1976
| Time | Auto | Athlete | Nationality | Location of race | Date |
| 47.8y | Maxie Long | New York, USA | September 29, 1900 | ||
| 48.2 | Charles Reidpath | Stockholm, Sweden | July 13, 1912 | ||
| 47.4y | Ted Meredith | Cambridge, USA | May 27, 1916 | ||
| 47.6 | Eric Liddell | Paris, France | July 11, 1924 | ||
| 47.0 | Emerson Spencer | Palo Alto, USA | May 12, 1928 | ||
| 46.4y | Ben Eastman | Palo Alto, California, USA | March 26, 1932 | ||
| 46.2 | 46.28 | Bill Carr | Los Angeles, USA | August 5, 1932 | |
| 46.1 | Archie Williams | Chicago, USA | June 19, 1936 | ||
| 46.0 | Rudolf Harbig | Frankfurt am Main, Germany | August 12, 1939 | ||
| 46.0 | Grover Klemmer | Philadelphia, USA | June 6, 1941 | ||
| 46.0y | Herb McKenley | Berkeley, USA | June 5, 1948 | ||
| 45.9 | 46.00 | Herb McKenley | Milwaukee, USA | July 2, 1948 | |
| 45.8 | George Rhoden | Eskilstuna, Sweden | August 22, 1950 | ||
| 45.4A | 45.68 | Lou Jones | Mexico City, Mexico | March 18, 1955 | |
| 45.2 | Lou Jones | Los Angeles, USA | June 30, 1956 | ||
| 44.9 | 45.07 | Otis Davis | Rome, Italy | September 6, 1960 | |
| 44.9 | 45.08 | Carl Kaufmann | Rome, Italy | September 6, 1960 | |
| 44.9y | Adolph Plummer | Tempe, USA | May 25, 1963 | ||
| 44.9 | Mike Larrabee | Los Angeles, USA | September 12, 1964 | ||
| 44.5+ | Tommie Smith | San Jose, USA | May 20, 1967 | ||
| 44.1A | 44.19 | Larry James | Echo Summit, USA | September 14, 1968 | |
| 43.8A | 43.86 | Lee Evans | Mexico City, Mexico | October 18, 1968 |
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.
Records post-1976
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 |
| 43.86 | Lee Evans | Mexico City, Mexico | October 18, 1968 | |
| 43.29 | Butch Reynolds | Zürich, Switzerland | August 17, 1988 | |
| 43.18 | Michael Johnson | Seville, Spain | August 26, 1999 | |
| 43.03 | Wayde van Niekerk | Rio de Janeiro, Brazil | August 14, 2016 |