| Event: | Men's 100 metre backstroke |
| Games: | 1928 Summer |
| Venue: | Olympic Sports Park Swim Stadium |
| Date: | 7–9 August |
| Competitors: | 19 |
| Nations: | 12 |
| Gold: | George Kojac |
| Goldnoc: | USA |
| Silver: | Walter Laufer |
| Silvernoc: | USA |
| Bronze: | Paul Wyatt |
| Bronzenoc: | USA |
| Prev: | 1924 |
| Next: | 1932 |
The men's 100 metre backstroke was a swimming event held as part of the swimming at the 1928 Summer Olympics programme.[1] It was the fifth appearance of the event, which was established in 1908. The competition was held from Tuesday to Thursday, 7 to 9 August 1928.
Nineteen swimmers from twelve nations competed.
These were the standing world and Olympic records (in minutes) prior to the 1928 Summer Olympics.
| World Record | 1:09.0 |  George Kojac | Detroit (U.S.) | 23 June 1928 | |
|---|---|---|---|---|---|
| Olympic Record | 1:13.2 | Warren Kealoha | Paris (FRA) | 18 July 1924 |
In the first heat George Kojac set a new Olympic record with 1:09.2 minutes. In the final he set a new world record with 1:08.2 minutes.
Tuesday 7 August 1928: The fastest two in each heat and the fastest third-placed from across the heats advanced. As there was a tie for second place in the fifth heat both swimmers advanced instead of a third placed.
| Rank | Swimmer | Nation | Time | Notes | |
|---|---|---|---|---|---|
| 1 | 1:09.2 | , | |||
| 2 | 1:13.4 | ||||
| 3 | 1:16.6 | ||||
| 4 | 1:17.4 |
| Rank | Swimmer | Nation | Time | Notes | |
|---|---|---|---|---|---|
| 1 | 1:12.8 | ||||
| 2 | 1:15.0 | ||||
| 3 | 1:15.6 | ||||
| 4 | 1:17.2 |
| Rank | Swimmer | Nation | Time | Notes | |
|---|---|---|---|---|---|
| 1 | 1:17.0 | ||||
| 2 | 1:18.8 | ||||
| 3 | 1:20.4 |
| Rank | Swimmer | Nation | Time | Notes | |
|---|---|---|---|---|---|
| 1 | 1:14.0 | ||||
| 2 | 1:16.4 | ||||
| 3 | 1:20.0 | ||||
| 4 | Unknown |
| Rank | Swimmer | Nation | Time | Notes | |
|---|---|---|---|---|---|
| 1 | 1:14.0 | ||||
| 2 | 1:14.4 | ||||
| 1:14.4 | |||||
| 4 | Unknown |
Wednesday 8 August 1928: The fastest three in each semi-final advanced.
| Rank | Swimmer | Nation | Time | Notes | |
|---|---|---|---|---|---|
| 1 | 1:10.0 | ||||
| 2 | 1:14.0 | ||||
| 3 | 1:14.8 | ||||
| 4 | Unknown | ||||
| 5 | Unknown | ||||
| 6 | Unknown |
| Rank | Swimmer | Nation | Time | Notes | |
|---|---|---|---|---|---|
| 1 | 1:12.6 | ||||
| 2 | 1:14.2 | ||||
| 1:14.2 | |||||
| 4 | Unknown | ||||
Thursday 9 August 1928:
| Rank | Swimmer | Nation | Time | Notes | |
|---|---|---|---|---|---|
| 1:08.2 | |||||
| 1:10.0 | |||||
| 1:12.0 | |||||
| 4 | 1:13.6 | ||||
| 5 | 1:13.8 | ||||
| 6 | 1:15.4 |