Athletics at the 1948 Summer Olympics – Men's 400 metres hurdles
The men's 400 metres hurdles event at the 1948 Summer Olympic Games took place July 30 and July 31. The final was won by American Roy Cochran.Records
Prior to the competition, the existing World and Olympic records were as follows.
The following new Olympic record was set during this competition:
| Date | Event | Athlete | Time | Notes |
| 31 July | Final | | 51.1 s | OR |
Schedule
All times are British Summer Time.
| Date | Time | |
| Friday, 30 July 1948 | 14:30
17:00 | Round 1
Semifinals |
| Saturday, 31 July 1948 | 15:30 | Final |
Results
Round 1
The first round was held on 30 July. The two fastest runners from each heat qualified to the semifinals.
Heat 1
| Rank | Name | Nationality | Time | Notes |
| 1 | Roy Cochran | | 53.9 | |
| 2 | Jacques André | | 54.5 | |
| 3 | Hermelindo Alberti | | 54.6 | |
| 4 | Jaime Aparicio | | 55.1 | |
Heat 2
| Rank | Name | Nationality | Time | Notes |
| 1 | Harry Whittle | | 56.9 | |
| 2 | Jean-Claude Arifon | | 56.9 | |
| 3 | Lazaros Petropoulakis | | 57.9 | |
| 4 | Mohsin Nazar Khan | | 59.5 | |
Heat 3
| Rank | Name | Nationality | Time | Notes |
| 1 | John Holland | | 54.6 | |
| 2 | Bebbe Storsrkubb | | 54.6 | |
| 3 | Kemal Horulu | | 55.1 | |
| 4 | Michael Pope | | 55.3 | |
Heat 4
| Rank | Name | Nationality | Time | Notes |
| 1 | Ottavio Missoni | | 53.9 | |
| 2 | Rune Larsson | | 54.5 | |
| 3 | Ron Unsworth | | 55.1 | |
| 4 | Sergio Guzmán | | 55.9 | |
| 5 | Mario Rosas | | 55.9 | |
Heat 5
| Rank | Name | Nationality | Time | Notes |
| 1 | Dick Ault | | 54.7 | |
| 2 | Yves Cros | | 55.7 | |
| 3 | Werner Christen | | 56.7 | |
| 4 | Ng Liang Chiang | | 57.7 | |
Heat 6
| Rank | Name | Nationality | Time | Notes |
| 1 | Duncan White | | 53.6 | |
| 2 | Jeff Kirk | | 54.3 | |
| 3 | Alf Westman | | 54.5 | |
| 4 | Bill LaRochelle | | 54.9 | |
Semifinals
The semifinals were held on 30 July. The three fastest runners from each heat advanced to the final.
Heat 1
| Rank | Name | Nationality | Time | Notes |
| 1 | Rune Larsson | | 51.9 | OR |
| 2 | Dick Ault | | 52.1 | |
| 3 | Duncan White | | 52.1 | |
| 4 | Jean-Claude Arifon | | 52.3 | |
| 5 | Jeff Kirk | | 52.5 | |
| 6 | Jacques André | | 56.3 | |
Heat 2
| Rank | Name | Nationality | Time | Notes |
| 1 | Roy Cochran | | 51.9 | = OR |
| 2 | Yves Cros | | 52.5 | |
| 3 | Ottavio Missoni | | 53.4 | |
| 4 | Harry Whittle | | 53.4 | |
| 5 | Bebbe Storsrkubb | | 53.5 | |
| 6 | John Holland | | 53.9 | |
Final
| Rank | Name | Nationality | Time | Notes |
| Roy Cochran | | 51.1 | OR |
| Duncan White | | 51.8 | |
| Rune Larsson | | 52.2 | |
| 4 | Dick Ault | | 52.4 | |
| 5 | Yves Cros | | 53.3 | |
| 6 | Ottavio Missoni | | 54.0 | |
Key: OR = Olympic record
