Medalists
| Gold |
 Aaron Peirsol
United States (USA) |
| Silver |
Matt Grevers
United States (USA) |
| Bronze |
 Arkady Vyatchanin
Russia (RUS) |
| Bronze |
 Hayden Stoeckel
Australia (AUS) |
Records
Prior to this competition, the existing world and Olympic records were as follows.
| World Record |
Aaron Peirsol (USA) |
52.89 |
Omaha, USA |
1 July 2008 |
| Olympic Record |
Aaron Peirsol (USA) |
53.45 |
Athens, Greece |
21 August 2004 |
Heats
| Rank |
Heat |
Lane |
Name |
Nationality |
Time |
Notes |
| 1 |
4 |
4 |
Matt Grevers |
United States |
0:53.41 |
Q, OR |
| 2 |
4 |
5 |
Arkady Vyatchanin |
Russia |
0:53.64 |
Q |
| 3 |
6 |
4 |
Aaron Peirsol |
United States |
0:53.65 |
Q |
| 4 |
6 |
7 |
Aschwin Wildeboer |
Spain |
0:53.67 |
Q |
| 5 |
3 |
5 |
Gerhard Zandberg |
South Africa |
0:53.75 |
Q |
| 6 |
6 |
5 |
Liam Tancock |
Great Britain |
0:53.85 |
Q |
| 7 |
5 |
3 |
Hayden Stoeckel |
Australia |
0:53.93 |
Q |
| 8 |
3 |
8 |
Lubos Krizko |
Slovakia |
0:54.07 |
Q |
| 9 |
5 |
5 |
Ashley Delaney |
Australia |
0:54.08 |
Q |
| 10 |
5 |
2 |
Junichi Miyashita |
Japan |
0:54.12 |
Q |
| 11 |
4 |
2 |
Stanislav Donets |
Russia |
0:54.18 |
Q |
| 12 |
4 |
3 |
Tomomi Morita |
Japan |
0:54.21 |
Q |
| 13 |
6 |
3 |
Markus Rogan |
Austria |
0:54.22 |
Q |
| 14 |
6 |
1 |
Mirco Di Tora |
Italy |
0:54.39 |
Q |
| 15 |
5 |
1 |
Guy Barnea |
Israel |
0:54.50 |
Q |
| 16 |
5 |
6 |
Gregor Tait |
Great Britain |
0:54.62 |
Q |
| 17 |
4 |
6 |
Aristeidis Grigoriadis |
Greece |
0:54.71 |
|
| 18 |
3 |
4 |
Damiano Lestingi |
Italy |
0:54.78 |
|
| 19 |
5 |
4 |
Helge Meeuw |
Germany |
0:54.88 |
|
| 20 |
6 |
2 |
Guilherme Guido |
Brazil |
0:54.89 |
|
| 21 |
6 |
8 |
Razvan Ionut Florea |
Romania |
0:54.89 |
|
| 22 |
4 |
8 |
George Du Rand |
South Africa |
0:54.90 |
|
| 23 |
3 |
7 |
Min Sung |
South Korea |
0:54.99 |
|
| 24 |
4 |
1 |
Gordan Kožulj |
Croatia |
0:55.05 |
|
| 25 |
3 |
3 |
Benjamin Stasiulis |
France |
0:55.08 |
|
| 26 |
2 |
6 |
Omar Pinzón |
Colombia |
0:55.11 |
|
| 27 |
3 |
6 |
Jonathan Massacand |
Switzerland |
0:55.21 |
|
| 28 |
4 |
7 |
Nick Driebrgen |
Netherlands |
0:55.31 |
|
| 29 |
2 |
5 |
Pavel Sankovich |
Belarus |
0:55.39 |
|
| 30 |
3 |
1 |
Derya Buyukuncu |
Turkey |
0:55.43 |
|
| 31 |
5 |
8 |
Jake Tapp |
Canada |
0:55.54 |
|
| 32 |
3 |
2 |
Vytautas Janusaitis |
Lithuania |
0:55.65 |
|
| 33 |
6 |
6 |
Thomas Rupprath |
Germany |
0:55.77 |
|
| 34 |
5 |
7 |
Marko Strahija |
Croatia |
0:55.89 |
|
| 35 |
2 |
4 |
Orn Arnarson |
Iceland |
0:56.15 |
|
| 36 |
2 |
3 |
Roland Rudolf |
Hungary |
0:56.25 |
|
| 37 |
2 |
2 |
Xiaolei Sun |
China |
0:56.44 |
|
| 38 |
2 |
8 |
Oleksandr Isakov |
Ukraine |
0:56.55 |
|
| 39 |
1 |
4 |
Danil Bugakov |
Uzbekistan |
0:56.59 |
|
| 40 |
2 |
7 |
German Eduardo Otero |
Argentina |
0:56.74 |
|
| 41 |
2 |
1 |
Tomáš Fučík |
Czech Republic |
0:57.29 |
|
| 42 |
1 |
3 |
Jared J Heine |
Marshall Islands |
0:58.86 |
|
| 43 |
1 |
2 |
Souhaib Kalala |
Syria |
1:00.24 |
|
| 44 |
1 |
6 |
Rubel Mohammad Rana |
Bangladesh |
1:04.82 |
|
Semifinals
| Rank |
Semifinal |
Lane |
Swimmer |
Time |
Notes |
| 1 |
2 |
6 |
Hayden Stoeckel (AUS) |
52.97 |
Q, OR |
| 2 |
2 |
4 |
Matt Grevers (USA) |
52.99 |
Q |
| 3 |
1 |
4 |
Arkady Vyatchanin (RUS) |
53.06 |
Q |
| 4 |
1 |
5 |
Aschwin Wildeboer (ESP) |
53.51 |
Q |
| 5 |
2 |
5 |
Aaron Peirsol (USA) |
53.56 |
Q |
| 6 |
1 |
3 |
Liam Tancock (GBR) |
53.61 |
Q |
| 7 |
1 |
2 |
Junichi Miyashita (JPN) |
53.69 |
Q |
| 8 |
2 |
2 |
Ashley Delaney (AUS) |
53.76 |
Q |
| 9 |
2 |
1 |
Markus Rogan (AUT) |
53.80 |
|
| 10 |
1 |
7 |
Tomomi Morita (JPN) |
53.95 |
|
| 11 |
2 |
3 |
Gerhard Zandberg (v) |
53.98 |
|
| 12 |
1 |
8 |
Gregor Tait (GBR) |
54.37 |
|
| 13 |
1 |
6 |
Lubos Krizko (SVK) |
54.38 |
|
| 14 |
2 |
7 |
Stanislav Donets (RUS) |
54.57 |
|
| 15 |
1 |
8 |
Mirco Di Tora (ITA) |
54.92 |
|
| 16 |
2 |
2 |
Guy Barnea (ISR) |
54.93 |
|
Final
| Rank |
Lane |
Swimmer |
Time |
Notes |
| 1 |
2 |
Aaron Peirsol (USA) |
0:52.54 |
WR |
| 2 |
5 |
Matt Grevers (USA) |
0:53.11 |
|
| 3 |
3 |
Arkady Vyatchanin (RUS) |
0:53.18 |
|
| 3 |
4 |
Hayden Stoeckel (AUS) |
0:53.18 |
|
| 5 |
8 |
> Ashley Delaney (AUS) |
0:53.31 |
|
| 6 |
7 |
Liam Tancock (GBR) |
0:53.39 |
NR |
| 7 |
6 |
Aschwin Wildeboer (ESP) |
0:53.51 |
|
| 8 |
1 |
Junichi Miyashita (JPN) |
0:53.99 |
|
|
