The first world record in the 400 m for men (athletics) was recognized by the International Amateur Athletics Federation, now known as World Athletics, in 1912. The IAAF ratified Charles Reidpath's 48.2 s 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.
Up to and including 2021, World Athletics has ratified 24 world records in the event.[1]
The following tables show the world record progression in the men's 400 metres, as ratified by World Athletics.