[2] The event was won by Ralph Craig of the United States, as the Americans swept the medals for a second time (previously having done so in 1904).

None of the 1908 medalists returned in 1912. Notable entrants included Erwin Kern, Emil Ketterer, and Richard Rau of Germany, who shared the unofficial world record; George Patching of South Africa, the 1912 AAA Championships winner;[3] and United States Olympic Trials winners Ira Courtney, Clement Wilson, and Howard Drew.

[4] Chile (disputed, as Luis Subercaseaux may have run in 1896), Iceland, Japan, Portugal, Russia, and Serbia were represented in the event for the first time.

The United States and Hungary were the only two nations to have appeared at each of the first five Olympic men's 100 metres events.

"[5] With both runners assured of advancement to the semifinals, they "ran the course very quietly" with Rice "breaking the tape easily ahead of" Smedmark.

[5] This was a close race between the top two placers, with d'Arcy "shak[ing] off" Povey at the end and winning "by a metre.

"[6] Jacobs matched the Olympic record in a tight heat, neck-and-neck with Wilson for most of the way before winning by "a hands-breadth.

"[6] McConnell led early but faltered at the end; Thomas passed him for the second qualifying spot "just before reaching the post.

He "led from start to finish, and gave the impression that he would be an easy winner, but Applegarth came on very quickly in the last 20 metres, and Lippincott had to do his very best in order to keep the lead.

Lindberg fell behind early, dropping to fourth place at the halfway mark, but challenged Patching with a "hard spurt" at the end.

The final featured eight false starts, one of which saw Craig and Lippincott fail to hear the recall gun and run to the finish line.

At the 75-metre mark, Craig was "a hand's-breadth" ahead of Patching and Meyer, with Lippincott and Belote another half-metre back.