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.^[1]
The following tables show the world record progression in the men's 400 metres, as ratified by the IAAF.

Records 1912–1976[edit]

Time	Auto	Athlete	Nationality	Location of race	Date
47.8y		Maxie Long	Image may be NSFW. Clik here to view. United States	New York, USA	September 29, 1900[1]
48.2		Charles Reidpath	Image may be NSFW. Clik here to view. United States	Stockholm, Sweden	July 13, 1912[1]
47.4y		Ted Meredith	Image may be NSFW. Clik here to view. United States	Cambridge, USA	May 27, 1916[1][2]
47.6		Eric Liddell	Image may be NSFW. Clik here to view. United Kingdom	Paris, France	July 11, 1924[1]
47.0		Emerson Spencer	Image may be NSFW. Clik here to view. United States	Palo Alto, USA	May 12, 1928[1]
46.4y		Ben Eastman	Image may be NSFW. Clik here to view. United States	Palo Alto, California, USA	March 26, 1932[1]
46.2	46.28	Bill Carr	Image may be NSFW. Clik here to view. United States	Los Angeles, USA	August 5, 1932[1]
46.1		Archie Williams	Image may be NSFW. Clik here to view. United States	Chicago, USA	June 19, 1936[1]
46.0		Rudolf Harbig	Image may be NSFW. Clik here to view. Germany	Frankfurt am Main, Germany	August 12, 1939[1]
		Grover Klemmer	Image may be NSFW. Clik here to view. United States	Philadelphia, USA	June 6, 1941[1][3]
46.0y		Herb McKenley	Image may be NSFW. Clik here to view. Jamaica	Berkeley, USA	June 5, 1948[1]
45.9	46.00	Herb McKenley	Image may be NSFW. Clik here to view. Jamaica	Milwaukee, USA	July 2, 1948[1]
45.4A	45.68	Lou Jones	Image may be NSFW. Clik here to view. United States	Mexico City, Mexico	March 18, 1955[1]
45.2		Lou Jones	Image may be NSFW. Clik here to view. United States	Los Angeles, USA	June 30, 1956[1]
44.9	45.07	Otis Davis	Image may be NSFW. Clik here to view. United States	Rome, Italy	September 6, 1960[1]
	45.08	Carl Kaufmann	Image may be NSFW. Clik here to view. Germany	Rome, Italy	September 6, 1960[1]
44.9y		Adolph Plummer	Image may be NSFW. Clik here to view. United States	Tempe, USA	May 25, 1963[1]
44.9		Mike Larrabee	Image may be NSFW. Clik here to view. United States	Los Angeles, USA	September 12, 1964[1]
44.5+		Tommie Smith	Image may be NSFW. Clik here to view. United States	San Jose, USA	May 20, 1967[1]
44.1A	44.19	Larry James	Image may be NSFW. Clik here to view. United States	Echo Summit, USA	September 14, 1968[1]
43.8A	43.86	Lee Evans	Image may be NSFW. Clik here to view. United States	Mexico City, Mexico	October 18, 1968[1]

(+) 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.

Records post-1976[edit]

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.^[1]
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	Image may be NSFW. Clik here to view. United States	Mexico City, Mexico	October 18, 1968[1]
43.29	Butch Reynolds	Image may be NSFW. Clik here to view. United States	Zürich, Switzerland	August 17, 1988[1]
43.18	Michael Johnson	Image may be NSFW. Clik here to view. United States	Seville, Spain	August 26, 1999[1]

References[edit]

[hide] v t e Athletics record progressions World 100 metres men women 200 metres men women 400 metres men women 4×100 metres men women 4×200 metres men 4×400 metres men women 800 metres 1000 metres 1500 metres Mile run 3000 metres men women 5000 metres 10,000 metres Marathon 10 km walk women 20 km walk men women 50 km walk men Women's 80 metres hurdles 110/100 metres hurdles men women 400 metres hurdles men women 3000 metres steeplechase High jump men outdoor men indoor women Long jump Triple jump Pole vault men outdoor men indoor women Discus men women Hammer men women Javelin men women Shot put men women Decathlon Heptathlon men women Pentathlon European 100 metres men 200 metres men 400 metres men 800 metres men 1500 metres men 5000 metres men List of world records in athletics