1921 Finnish championships in aquatics
From 1906 to 1926, the Finnish Swimming Federation did not arrange a dedicated national competition, but spread out the hosting duties of the championship events to multiple clubs.
Artistic swimming
Men
Competed in Helsinki on 6 and 7 August 1921.| Rank | Name | Placing figure | Score |
| Eino Karjalainen | 3 | 395.66 points | |
| Onni Salonius | 6 | 388.66 points |
Source:
Women
Competed in Vyborg on 23 and 24 July 1921.| Rank | Name | Placing figure | Score |
| Magda Odén | 3 | 450.05 points | |
| Meeri Statschkun | 6 | 424.10 points |
Source:
Diving
Men
Plain
Competed in Helsinki on 29 and 31 July 1921.Final
Source:Platform
Competed in Helsinki on 30 and 31 July 1921.Source:
Springboard
Competed in Helsinki on 29 and 30 July 1921.| Rank | Name | Placing figure | Score |
| Oskar Wetzell | 4 | 147.60 points | |
| A. Lindqvist | 7 | 140.93 points | |
| L. Kyöstilä | 8 | 141.90 points | |
| 4 | A. Nyman | 12 | 129.62 points |
| 5 | Kalle Kainuvaara | 15 | 131.38 points |
| 6 | U. Mulli | 17 | 112.33 points |
| 7 | H. Petas | 21 | 82.10 points |
Source:
Women
Platform
Competed in Vyborg on 24 July 1921.| Rank | Name | Placing figure | Score |
| Helga Markelin | 5.5 | 99.25 points | |
| Liisa Lehmus | 6.5 | 98.25 points | |
| Aini Ohlsson | 7 | 98.25 points | |
| 4 | Kerttu Kainuvaara | 10 | 89.25 points |
Source:
Swimming
Men
100 metre freestyle
Competed in Helsinki on 31 July 1921.| Rank | Name | Time |
| Jussi Kahma | 1:11.8 | |
| G. Wasastjerna | 1:12.9 | |
| A. Eklund | 1:15.8 | |
| 4 | H. Belevicz | 1:17.7 |
| 5 | V. Lahtinen | 1:28.9 |
Source:
200 metre freestyle
Competed in Helsinki on 30 July 1921.| Rank | Name | Time |
| Armas Koskinen | 3:00.0 | |
| Jaakko Tiiainen | 3:00.0 | |
| Jussi Kahma | 3:01.0 | |
| 4 | Emil Koskinen | 3:07.7 |
| 5 | A. Viklund | 3:11.6 |
| 6 | Reino Mallenius | 3:15.2 |
| 7 | A. Eklund | 3:17.7 |
Source:
500 metre freestyle
Competed in Helsinki on 6 August 1921.| Rank | Name | Time |
| Armas Koskinen | 9:39.1 | |
| Emil Koskinen | 9:40.7 | |
| Jaakko Tiiainen | 9:48.4 | |
| 4 | Reino Mallenius | 9:53.3 |
| 5 | Viljo Viklund | 9:54.2 |
Source:
1000 metre freestyle
Competed in Helsinki on 7 August 1921.| Rank | Name | Time |
| Jaakko Tiiainen | 19:39.8 | |
| Emil Koskinen | 20:03.5 | |
| Viljo Viklund | 20:54.1 | |
| 4 | Reino Mallenius | 20:59.7 |
Source:
100 metre backstroke
Competed in Turku on 24 July 1921.| Rank | Name | Time |
| Viljo Viklund | 1:35.3 | |
| L. Heinonen | 1:36.2 | |
| Reino Mallenius | 1:36.3 | |
| 4 | V. Lahtinen | 1:39.8 |
| 5 | E. Vatanen | ? |
Source:
200 metre breaststroke
Competed in Turku on 24 July 1921.| Rank | Name | Time |
| Arvo Aaltonen | 3:07.1 | |
| Viljo Viklund | 3:07.5 | |
| V. Lehtinen | 3:29.0 | |
| 4 | Reino Mallenius | 3:29.5 |
| 5 | K. Lundstedt | ? |
Source:
100 metre life saving
Competed in Turku on 24 July 1921.| Rank | Name | Time |
| Jussi Kahma | 1:24.0 | |
| A. Eklund | 1:26.4 | |
| L. Heinonen | 1:30.8 |
Source:
4 × 50 metre freestyle relay
Competed in Helsinki on 29 July 1921.| Rank | Club | Team | Time |
| Vaasan Uimaseura | Ketola, Hellman, Jussi Kahma, A. Enegrén | 2:03.3 | |
| Helsingfors Simsällskap | H. Salmi, A. Belewitcz, H. Belewitcz, G. Wasastjerna | 2:06.6 | |
| Helsingin Uimarit | Jaakko Tiiainen, Kunnas, L. Saastamoinen, Armas Koskinen | 2:07.4 |
Source:
4 × 100 metre freestyle relay
Competed in Helsinki on 30 July 1921.| Rank | Club | Team | Time |
| Vaasan Uimaseura | Aaltonen, Ketola, A. Enegrén, Jussi Kahma | 4:59.4 | |
| Helsingfors Simsällskap | W. Belewitsch, A. Belewitsch, H. Salmi, G. Wasastjerna | 5:09.7 | |
| Helsingin Uimarit | Jaakko Tiiainen, A. Järvinen, Vihavainen, Armas Koskinen | 5:10.0 |
Source:
Women
50 metre freestyle
Competed in Vyborg on 24 July 1921.Final
Source:100 metre freestyle
Competed in Vyborg on 23 July 1921.| Rank | Name | Time |
| Elin Väkevä | 1:32.3 | |
| Anna Järvinen | 1:35.0 | |
| Elina Savelainen | 1:47.0 |
Source:
500 metre freestyle
Competed in Vyborg on 23 July 1921.| Rank | Name | Time |
| Liisa Lehmus | 9:45.3 NR | |
| Mary Lindberg | 10:11.3 | |
| Inkeri Kaltto | 10:37.6 |
Source:
100 metre breaststroke
Competed in Vyborg on 24 July 1921.| Rank | Name | Time |
| Liisa Lehmus | 1:40.7 | |
| Mary Lindberg | 1:47.0 | |
| Ester Lehmus | 1:50.0 | |
| 4 | Hilda Kuusela | ? |
Source:
4 × 50 metre freestyle relay
Competed in Vyborg on 23 July 1921.| Rank | Club | Team | Time |
| Viipurin Uimaseura | Arla Salonius, Elvi Väkevä, Liisa Lehmus, Elin Väkevä | 2:39.0 NR | |
| Helsingin Uimarit | Hellin Kahila, Hilda Kuusela, Helvi Mäkinen, Anna Järvinen | 2:44.1 | |
| Viipurin Uimaseura | Markkanen, Inkeri Kaltto, Elina Savelainen, Uimi | 3:07.2 |
Source: