| 3rd European Aquatics Championships | |
| Host City: | Paris |
| Country: | France |
| Events: | 16 |
| Previous: | Bologna 1927 |
The 1931 LEN European Aquatics Championships were held from 23 to 30 August in Paris, France.
| 3 m springboard | Ewald Riebschläger | 136.22 | Maurice Lepage | 135.32 | Willi Neumann | 134.38 | |
| Platform | Josef Staudinger | 111.82 | Willi Neumann | 108.90 | Ewald Riebschläger | 107.96 |
| 3 m springboard | Olga Jordan | 77.00 | Madi Epply | 72.86 | ? Schlüter | 69.?? | |
| Platform | Madi Epply | 34.28 | Ingeborg Sjöqvist | 33.62 | R Cretté-Flavier | 32.94 |
| 100 m freestyle | István Bárány | 59.8 | András Székely | 1:00.8 | Pavel Steiner | 1:03.0 | |
| 400 m freestyle | István Bárány | 5:04.0 | Jean Taris | 5:04.2 | Paolo Costoli | 5:16.8 | |
| 1500 m freestyle | Olivér Halassy | 20:49.0 | Giuseppe Perentin | 20:50.6 | Paolo Costoli | 21:09.4 | |
| 100 m backstroke | Gerhard Deutsch | 1:14.8 | Aladár Bitskey | 1:15.8 | Károly Nagy | 1:16.2 | |
| 200 m breaststroke | Ivo Reingoldt | 2:52.2 | Karl Wittenberg | 2:54.4 | Erwin Sietas | 2:55.0 | |
| 4×200 m freestyle relay | András Wanié László Szabados András Székely István Bárány | 9:34.0 WR | Karl Schubert Raimund Deiters Hans Balk Herbert Heinrich | 9:48.6 | Antonio Conelli Sirio Bianchini Ettore Baldo Paolo Costoli | 9:49.0 |
| 100 m freestyle | Yvonne Godard | 1:10.0 | Willy den Ouden | 1:11.8 | Joyce Cooper | 1:12.0 | |
| 400 m freestyle | Marie Braun | 5:42.0 | Joyce Cooper | 5:54.0 | Yvonne Godard | 5:55.4 | |
| 100 m backstroke | Marie Braun | 1:22.8 | Joyce Cooper | 1:23.6 | Phyllis Harding | 1:24.8 | |
| 200 m breaststroke | Cecelia Wolstenholme | 3:16.4 | Jenny Kastein | 3:18.2 | Margery Hinton | 3:20.4 | |
| 4×100 m freestyle relay | Truus Baumeister Maria Vierdag Willy den Ouden Marie Braun | 4:55.0 | Valerie Davies Phyllis Harding Jean McDowell Joyce Cooper | 5:00.8 | Margit Mallasz Ilona Tóth Margit Sipos Magda Lenkei | 5:02.2 |
| Men's tournament |