| Date | 5 – 7 August 1948 |
|---|---|
| Status | Olympic |
| Location | Wembley Arena, Wembley, London |
| Participants | 19 from 11 countries |
The same protagonists from the 100 metres were favored in the 400m freestyle, although the American Ann Curtis was considered stronger at this event than at the shorter distances. The shock of the heats was the collapse of the 100m gold medalist and hot favorite, Greta Andersen, who blacked out in the water just beyond the 200m mark and had to be rescued from the pool. Karen Margrethe Harup, also of Denmark, broke the Olympic record in the semi-finals and emerged as the greatest threat to an American victory.
In the final, Curtis held her effort until the final 100m, and then breezed past the opposition to record a clear victory. Harup narrowly held on to silver, with a fast finishing Cathie Gibson gaining the host nation’s only aquatic medal of the 1948 games with her bronze.
| Pos | Number | Competitor | NOC | R1 | SF | Final | |||
|---|---|---|---|---|---|---|---|---|---|
| 1 | – | Ann Curtis |  USA | 5:32.0 (2 h1) | 5:26.4 (1 h2) | 5:17.8 (1) | Gold | ||
| 2 | 423 | Karen Margrethe Harup |  DEN | 5:31.7 (1 h1) | 5:25.7 (1 h1) | 5:21.2 (2) | Silver | ||
| 3 | 451 | Cathie Gibson |  GBR | 5:26.9 (1 h2) | 5:31.0 (4 h2) | 5:22.5 (3) | Bronze | ||
| 4 | 414 | Fernande Caroen |  BEL | 5:29.2 (2 h2) | 5:26.1 (2 h1) | 5:25.3 (4) | |||
| 5 | 441 | Brenda Helser | USA | 5:30.0 (=1 h3) | 5:28.1 (2 h2) | 5:26.0 (5) | |||
| 6 | 417 | Piedade Coutinho-Tavares |  BRA | 5:30.0 (=1 h3) | 5:31.1 (3 h1) | 5:29.4 (6) | |||
| 7 | 422 | Fritze Carstensen | DEN | 5:29.4 (3 h2) | 5:29.5 (3 h2) | 5:29.4 (7) | |||
| 8 | 488 | Nancy Lees | USA | 5:29.6 (4 h2) | 5:31.9 (4 h1) | 5:32.9 (8) | |||
| 9 | 486 | Colette Thomas |  FRA | 5:32.9 (3 h1) | 5:35.3 (5 h2) | – | |||
| 10 | 413 | Denise Spencer |  AUS | 5:40.9 (4 h3) | 5:35.6 (6 h2) | – | |||
| 11 | 429 | Margaret Wellington | GBR | 5:40.0 (5 h1) | 5:38.2 (7 h2) | – | |||
| 12 | 427 | Pat Nielsen | GBR | 5:40.4 (3 h3) | 5:39.5 (5 h1) | – | |||
| 13 | 436 | Magda Brüggemann |  MEX | 5:43.8 (5 h3) | 5:42.4 (6 h1) | – | |||
| 14 | 411 | Eileen Holt |  ARG | 5:44.9 (6 h3) | 5:52.4 (8 h2) | – | |||
| 15 | 420 | Vivian King |  CAN | 5:54.8 (5 h2) | 5:52.7 (7 h1) | – | |||
| 16 | 487 | Gisela Thidholm |  SWE | 5:34.5 (4 h1) | – (DNS h1) | – | |||
| 17 | – | Kay McNamee | CAN | 5:58.7 (6 h1) | – | – | |||
| 18 | 410 | Enriqueta Duarte | ARG | 6:14.4 (7 h1) | – | – | |||
| 421 | Greta Andersen | DEN | – (DNF h3) | – | – | ||||
| 485 | Talita Rodrígues | BRA | – (DNS h2) | – | – | ||||
| 424 | Josette Arène | FRA | – (DNS h3) | – | – | ||||
| 477 | Éva Székely |  HUN | – (DNS h2) | – | – | ||||
| 431 | Hannie Termeulen |  NED | – (DNS h1) | – | – |
| Date | 5 August 1948 — 16:00 |
|---|---|
| Format | Top four in each heat and the next four fastest advanced to the semi-finals. |
| Pos | Lane | Competitor | NOC | Time | ||
|---|---|---|---|---|---|---|
| 1 | 3 | Cathie Gibson | GBR | 5:26.9 | ||
| 2 | 2 | Fernande Caroen | BEL | 5:29.2 | ||
| 3 | 1 | Fritze Carstensen | DEN | 5:29.4 | ||
| 4 | 6 | Nancy Lees | USA | 5:29.6 | ||
| =5 | 1 | Brenda Helser | USA | 5:30.0 | ||
| =5 | 2 | Piedade Coutinho-Tavares | BRA | 5:30.0 | 1 | |
| 7 | 3 | Karen Margrethe Harup | DEN | 5:31.7 | ||
| 8 | 7 | Ann Curtis | USA | 5:32.0 | ||
| 9 | 5 | Colette Thomas | FRA | 5:32.9 | ||
| 10 | 8 | Gisela Thidholm | SWE | 5:34.5 | ||
| 11 | 1 | Margaret Wellington | GBR | 5:40.0 | ||
| 12 | 7 | Pat Nielsen | GBR | 5:40.4 | ||
| 13 | 8 | Denise Spencer | AUS | 5:40.9 | ||
| 14 | 6 | Magda Brüggemann | MEX | 5:43.8 | ||
| 15 | 4 | Eileen Holt | ARG | 5:44.9 | ||
| 16 | 5 | Vivian King | CAN | 5:54.8 | ||
| 17 | 4 | Kay McNamee | CAN | 5:58.7 | ||
| 18 | 6 | Enriqueta Duarte | ARG | 6:14.4 | ||
| 3 | Greta Andersen | DEN | – | |||
| 2 | Hannie Termeulen | NED | – | |||
| 4 | Talita Rodrígues | BRA | – | |||
| 7 | Éva Székely | HUN | – | |||
| 5 | Josette Arène | FRA | – |
| Pos | Lane | Competitor | NOC | Time | ||
|---|---|---|---|---|---|---|
| 1 | 3 | Karen Margrethe Harup | DEN | 5:31.7 | ||
| 2 | 7 | Ann Curtis | USA | 5:32.0 | ||
| 3 | 5 | Colette Thomas | FRA | 5:32.9 | ||
| 4 | 8 | Gisela Thidholm | SWE | 5:34.5 | ||
| 5 | 1 | Margaret Wellington | GBR | 5:40.0 | ||
| 6 | 4 | Kay McNamee | CAN | 5:58.7 | ||
| 7 | 6 | Enriqueta Duarte | ARG | 6:14.4 | ||
| 2 | Hannie Termeulen | NED | – |
| Pos | Lane | Competitor | NOC | Time | ||
|---|---|---|---|---|---|---|
| 1 | 3 | Cathie Gibson | GBR | 5:26.9 | ||
| 2 | 2 | Fernande Caroen | BEL | 5:29.2 | ||
| 3 | 1 | Fritze Carstensen | DEN | 5:29.4 | ||
| 4 | 6 | Nancy Lees | USA | 5:29.6 | ||
| 5 | 5 | Vivian King | CAN | 5:54.8 | ||
| 4 | Talita Rodrígues | BRA | – | |||
| 7 | Éva Székely | HUN | – |
| Pos | Lane | Competitor | NOC | Time | ||
|---|---|---|---|---|---|---|
| =1 | 1 | Brenda Helser | USA | 5:30.0 | ||
| =1 | 2 | Piedade Coutinho-Tavares | BRA | 5:30.0 | 2 | |
| 3 | 7 | Pat Nielsen | GBR | 5:40.4 | ||
| 4 | 8 | Denise Spencer | AUS | 5:40.9 | ||
| 5 | 6 | Magda Brüggemann | MEX | 5:43.8 | ||
| 6 | 4 | Eileen Holt | ARG | 5:44.9 | ||
| 3 | Greta Andersen | DEN | – | |||
| 5 | Josette Arène | FRA | – |
| Date | 6 August 1948 — 11:00 |
|---|---|
| Format | Top three in each heat and the next two fastest advanced to the final. |
| Pos | Lane | Competitor | NOC | Time | ||
|---|---|---|---|---|---|---|
| 1 | 3 | Karen Margrethe Harup | DEN | 5:25.7 | ||
| 2 | 5 | Fernande Caroen | BEL | 5:26.1 | ||
| 3 | 3 | Ann Curtis | USA | 5:26.4 | ||
| 4 | 6 | Brenda Helser | USA | 5:28.1 | ||
| 5 | 4 | Fritze Carstensen | DEN | 5:29.5 | ||
| 6 | 5 | Cathie Gibson | GBR | 5:31.0 | ||
| 7 | 6 | Piedade Coutinho-Tavares | BRA | 5:31.1 | ||
| 8 | 4 | Nancy Lees | USA | 5:31.9 | ||
| 9 | 7 | Colette Thomas | FRA | 5:35.3 | ||
| 10 | 8 | Denise Spencer | AUS | 5:35.6 | ||
| 11 | 2 | Margaret Wellington | GBR | 5:38.2 | ||
| 12 | 2 | Pat Nielsen | GBR | 5:39.5 | ||
| 13 | 8 | Magda Brüggemann | MEX | 5:42.4 | ||
| 14 | 1 | Eileen Holt | ARG | 5:52.4 | ||
| 15 | 1 | Vivian King | CAN | 5:52.7 | ||
| 7 | Gisela Thidholm | SWE | – |
| Pos | Lane | Competitor | NOC | Time | ||
|---|---|---|---|---|---|---|
| 1 | 3 | Karen Margrethe Harup | DEN | 5:25.7 | ||
| 2 | 5 | Fernande Caroen | BEL | 5:26.1 | ||
| 3 | 6 | Piedade Coutinho-Tavares | BRA | 5:31.1 | ||
| 4 | 4 | Nancy Lees | USA | 5:31.9 | ||
| 5 | 2 | Pat Nielsen | GBR | 5:39.5 | ||
| 6 | 8 | Magda Brüggemann | MEX | 5:42.4 | ||
| 7 | 1 | Vivian King | CAN | 5:52.7 | ||
| 7 | Gisela Thidholm | SWE | – |
| Pos | Lane | Competitor | NOC | Time | ||
|---|---|---|---|---|---|---|
| 1 | 3 | Ann Curtis | USA | 5:26.4 | ||
| 2 | 6 | Brenda Helser | USA | 5:28.1 | ||
| 3 | 4 | Fritze Carstensen | DEN | 5:29.5 | ||
| 4 | 5 | Cathie Gibson | GBR | 5:31.0 | ||
| 5 | 7 | Colette Thomas | FRA | 5:35.3 | ||
| 6 | 8 | Denise Spencer | AUS | 5:35.6 | ||
| 7 | 2 | Margaret Wellington | GBR | 5:38.2 | ||
| 8 | 1 | Eileen Holt | ARG | 5:52.4 |
| Date | 7 August 1948 — 15:00 |
|---|
| Pos | Lane | Competitor | NOC | Time | ||
|---|---|---|---|---|---|---|
| 1 | 6 | Ann Curtis | USA | 5:17.8 | ||
| 2 | 5 | Karen Margrethe Harup | DEN | 5:21.2 | ||
| 3 | 2 | Cathie Gibson | GBR | 5:22.5 | ||
| 4 | 4 | Fernande Caroen | BEL | 5:25.3 | ||
| 5 | 3 | Brenda Helser | USA | 5:26.0 | ||
| 6 | 8 | Piedade Coutinho-Tavares | BRA | 5:29.4 | ||
| 7 | 7 | Fritze Carstensen | DEN | 5:29.4 | ||
| 8 | 1 | Nancy Lees | USA | 5:32.9 |
