Athletics at the 1964 Summer Olympics – Men's 800 metres

The runners used a crouch start without blocks and a single turn stagger start (breaking after the first turn). Returning to the final from four years earlier were defending champion Peter Snell and bronze medalist George Kerr. While Snell started strongly, he found himself in third place at the break, led by aggressive front-running by Wilson Kiprugut. As others moved forward, Snell found himself boxed along the rail, so as the runners came onto the home stretch he had to slow to come out the back of the box, then as the bell approached, he glided along the outside to catch up to Kiprugut and Kerr in the lead. With free running room, Snell kept going, taking the lead on the penultimate turn. After establishing a three-metre lead, he held his position, even extending it a little to take the repeat gold. Down the backstretch, Bill Crothers made his way around Kiprugut while Kerr was trying to chase down Snell. Crothers came off the final turn with more speed, passing Kerr on the home stretch. Kerr began to struggle. Snell was too far ahead for Crothers to catch, but Kiprugut closed down on Kerr, passing him and sealing the bronze medal with a dip at the finish.

Snell became the third to defend his 800-metre title after Douglas Lowe and Mal Whitfield. The feat would not be accomplished again for 52 years until David Rudisha repeated in 2016. Kiprugut won Kenya's first ever Olympic medal, unleashing a floodgate of national dominance in distance running events, particularly the 3000 meters steeplechase in subsequent Olympics.

This was the 15th appearance of the event, which is one of 12 athletics events to have been held at every Summer Olympics. Three finalists from 1960 returned: gold medalist Peter Snell of New Zealand, bronze medalist George Kerr of Jamaica, and sixth-place finisher Manfred Matuschewski of the United Team of Germany. Snell had broken the 800 metres world record as well as the one-mile world record, and was a favorite to repeat.[1]

Chad, Colombia, Hong Kong, Iran, Malaysia, Mongolia, and Tanzania appeared in the event for the first time. Great Britain and the United States each made their 14th appearance, tied for the most among all nations.

After one Games of a four-round format in 1960, the competition returned to the three-round format used in most Games since 1912 (other than 1960, the only other deviation was in 1936 when there were only two rounds due to a small number of entrants). The final, which had been 9 men from 1920 to 1952, 8 in 1956, and only 6 in 1960, was back up to 8 men. The 1964 competition introduced the "fastest loser" system, used only in the semifinals at this edition. Previously, advancement depended solely on the runners' place in their heat. The 1964 competition added advancement places to the fastest runners across the heats in the semifinals who did not advance based on place.

There were six first-round heats, each with 7 or 8 athletes; the top four runners in each heat advanced to the semifinals. There were three semifinals with 8 athletes each; the top two runners in each semifinal, and the next two fastest overall, advanced to the eight-man final.[1][3]

These were the standing world and Olympic records (in minutes) prior to the 1948 Summer Olympics.

World record	Peter Snell (NZL)	1:44.3	Christchurch, New Zealand	2 February 1962
Olympic record	Peter Snell (NZL)	1:46.48	Rome, Italy	2 September 1960

In the second semifinal, George Kerr and Wilson Kiprugut each finished at 1:46.1 to set a new, though short-lived, Olympic record. The final saw four runners break that new record, with Peter Snell's gold-medal winning 1:45.1 the new record afterward.

All times are Japan Standard Time (UTC+9)