# List of junior world records in swimming

The Junior World Records in Swimming are the fastest times ever swum by a "junior" swimmer, with junior defined as the following ages (age as of December 31 of the year of the swim):
* girls - 18 years old or younger
* boys - 18 years old or younger
These records are kept/maintained by the FINA (now World Aquatics), and were initially established in March 2014 and based on the meet records from the Junior Worlds meet.
Note: in some cases, there were existing world records (e.g. Katie Ledecky's 400, 800 and 1500 m freestyle, Rūta Meilutytė's 100 m breaststroke) that were not considered for these records (but were faster). Likewise more historical times by juniors were also not considered (e.g. Mary T. Meagher's 2:05.96 in the 200 m butterfly).
Long Course records can be established by breaking the initial time at a meet after April 1, 2014. FINA World Junior Records in 25m pool are recognised starting on January 1, 2015.
Records are recognized for long course (50 m pool) and short course (25 m pool) in the following events:
* freestyle: 50, 100, 200, 400, 800 and 1500;
* backstroke: 50, 100 and 200;
* breaststroke: 50, 100 and 200;
* butterfly: 50, 100 and 200;
* Individual medley: 100 (short course only), 200 and 400;
* relays: 4×50 free (short course only), 4×100 free, 4×200 free, 4×50 medley (short course only) and 4×100 medley.
Also recognized are mixed relay records for 4 × 100 medley and free relays.
All records were swum in finals unless noted otherwise.

## Long Course (50 m)
### Boys

| Event | Time | | Name | Nationality | Date | Meet | Location | Ref |
| 50m freestyle | 21.75 | h, = | Michael Andrew | United States | 25 August 2017 | World Junior Championships | Indianapolis, United States | |
| 50m freestyle | 21.75 | = | Michael Andrew | United States | 26 August 2017 | World Junior Championships | Indianapolis, United States | |
| 100m freestyle | 46.86 | ER | David Popovici | Romania | 13 August 2022 | European Championships | Rome, Italy | |
| 200m freestyle | 1:42.97 | | David Popovici | Romania | 15 August 2022 | European Championships | Rome, Italy | link |
| 400m freestyle | 3:44.31 | | Petar Mitsin | Bulgaria | 9 July 2023 | European Junior Championships | Belgrade, Serbia | |
| 400m freestyle | 3:40.59 | not ratified, fastest all-time junior | Ian Thorpe | Australia | 16 September 2000 | Olympic Games | Sydney, Australia | |
| 800m freestyle | 7:43.37 | | Lorenzo Galossi | Italy | 13 August 2022 | European Championships | Rome, Italy | |
| 1500m freestyle | 14:41.22 | | Kuzey Tunçelli | Turkey | 4 August 2024 | Olympic Games | Paris, France | |
| 50m backstroke | 24.00 | | Kliment Kolesnikov | Russia | 4 August 2018 | European Championships | Glasgow, United Kingdom | |
| 100m backstroke | 52.08 | r | Miron Lifintsev | Russia | 28 July 2024 | Russian Cup | Yekaterinburg, Russia | |
| 200m backstroke | 1:55.14 | | Kliment Kolesnikov | Russia | 28 July 2017 | World Championships | Budapest, Hungary | |
| 200m backstroke | 1:54.77 | not ratified, fastest all-time junior | Ryosuke Irie | Japan | 7 June 2008 | Japan Open | Tokyo, Japan | |
| 50m breaststroke | 26.97 | h | Nicolò Martinenghi | Italy | 4 April 2017 | Italian Championships | Riccione, Italy | |
| 100m breaststroke | 59.01 | sf | Nicolò Martinenghi | Italy | 23 August 2017 | World Junior Championships | Indianapolis, United States | |
| 200m breaststroke | 2:08.04 | | Dong Zhihao | China | 28 July 2023 | World Championships | Fukuoka, Japan | |
| 200m breaststroke | 2:07.35 | not ratified | Qin Haiyang | China | 4 September 2017 | National Games | Tianjin, China | |
| 200m breaststroke | 2:07.01 | not ratified, fastest all-time junior | Akihiro Yamaguchi | Japan | 15 September 2012 | National Sports Festival | Gifu, Japan | |
| 50m butterfly | 22.96 | | Diogo Ribeiro | Portugal | 3 September 2022 | World Junior Championships | Lima, Peru | link |
| 100m butterfly | 50.62 | | Kristóf Milák | Hungary | 29 July 2017 | World Championships | Budapest, Hungary | |
| 200m butterfly | 1:53.79 | | Kristóf Milák | Hungary | 30 June 2017 | European Junior Championships | Netanya, Israel | |
| 200m butterfly | 1:52.71 | not ratified, fastest all-time junior | Kristóf Milák | Hungary | 28 March 2018 | Hungarian Championships | Debrecen, Hungary | |
| 200m individual medley | 1:56.99 | sf | Hubert Kós | Hungary | 19 May 2021 | European Championships | Budapest, Hungary | |
| 200m individual medley | 1:55.94 | not ratified, fastest all-time junior | Michael Phelps | United States | 9 August 2003 | USA Championships | College Park, United States | |
| 400m individual medley | 4:10.02 | | Ilya Borodin | Russia | 23 May 2021 | European Championships | Budapest, Hungary | |
| 400m individual medley | 4:08.94 | not ratified, fastest all-time junior | Kosuke Hagino | Japan | 28 July 2012 | Olympic Games | London, United Kingdom | |
| 4 × 100m freestyle relay | 3:15.49 | | Daniel Diehl (49.93)Maximus Williamson (47.78)Hudson Williams (49.14)Jason Zhao (48.64) | United States | 4 September 2023 | World Junior Championships | Netanya, Israel | |
| 4 × 200m freestyle relay | 7:08.37 | | Jake Magahey (1:48.11)Luca Urlando (1:47.13)Jake Mitchell (1:47.03)Carson Foster (1:46.10) | United States | 23 August 2019 | World Junior Championships | Budapest, Hungary | |
| 4 × 100m medley relay | 3:33.19 | | Nikolay Zuev (53.84)Vladislav Gerasimenko (59.53)Andrey Minakov (50.93)Aleksandr Shchegolev (48.89) | Russia | 25 August 2019 | World Junior Championships | Budapest, Hungary | |

### Girls

| Event | Time | | Name | Nationality | Date | Meet | Location |
| 50m freestyle | 24.17 | | Claire Curzan | United States | 14 May 2021 | TAC Titans Spring Invitational Meet | Cary, United States |
| 50m freestyle | 23.99 | not ratified, fastest all-time junior | Cate Campbell | Australia | 2 August 2009 | World Championships | Rome, Italy |
| 100m freestyle | 52.70 | | Penny Oleksiak | Canada | 11 August 2016 | Olympic Games | Rio de Janeiro, Brazil |
| 100m freestyle | 52.49 | not ratified, fastest all-time junior | Mollie O'Callaghan | Australia | 18 May 2022 | Australian Championships | Adelaide, Australia |
| 200m freestyle | 1:53.65 | | Summer McIntosh | Canada | 26 July 2023 | World Championships | Fukuoka, Japan |
| 400m freestyle | 3:56.08 | AM | Summer McIntosh | Canada | 28 March 2023 | Canadian Trials | Toronto, Canada |
| 800m freestyle | 8:11.00 | | Katie Ledecky | United States | 22 June 2014 | Woodlands Senior Invitational Meet | Shenandoah, United States |
| 800m freestyle | 8:07.39 | not ratified, fastest all-time junior | Katie Ledecky | United States | 8 August 2015 | World Championships | Kazan, Russia |
| 1500m freestyle | 15:28.36 | | Katie Ledecky | United States | 24 August 2014 | Pan Pacific Championships | Gold Coast, Australia |
| 1500m freestyle | 15:25.48 | not ratified, fastest all-time junior | Katie Ledecky | United States | 4 August 2015 | World Championships | Kazan, Russia |
| 50m backstroke | 27.49 | | Minna Atherton | Australia | 7 February 2016 | Brisbane Sprint Championships | Brisbane, Australia |
| 50m backstroke | 27.22 | not ratified, fastest all-time junior | Fu Yuanhui | China | 1 April 2013 | Chinese Nationals | Zhengzhou, China |
| 100m backstroke | 57.57 | r | Regan Smith | United States | 28 July 2019 | World Championships | Gwangju, South Korea |
| 200m backstroke | 2:03.35 | sf, AM | Regan Smith | United States | 26 July 2019 | World Championships | Gwangju, South Korea |
| 50m breaststroke | 29.30 | sf | Benedetta Pilato | Italy | 22 May 2021 | European Championships | Budapest, Hungary |
| 100m breaststroke | 1:04.35 | sf, ER | Rūta Meilutytė | Lithuania | 29 July 2013 | World Championships | Barcelona, Spain |
| 200m breaststroke | 2:19.64 | | Viktoriya Zeynep Gunes | Turkey | 30 August 2015 | World Junior Championships | Singapore, Singapore |
| 50m butterfly | 25.46 | | Rikako Ikee | Japan | 26 August 2017 | World Junior Championships | Indianapolis, United States |
| 50m butterfly | 25.11 | not ratified, fastest all-time junior | Rikako Ikee | Japan | 10 June 2018 | Mare Nostrum | Canet-en-Roussillon, France |
| 100m butterfly | 56.33 | | Mizuki Hirai | Japan | 22 June 2024 | Kanagawa Prefectural High School General Athletic Meet | Kanagawa, Japan |
| 100m butterfly | 56.20 | not ratified | Claire Curzan | United States | 10 April 2021 | TAC Titans Premier Invitational | Cary, United States |
| 100m butterfly | 56.06 | not ratified, fastest all-time junior | Sarah Sjöström | Sweden | 27 July 2009 | World Championships | Rome, Italy |
| 200m butterfly | 2:03.03 | AM | Summer McIntosh | Canada | 1 August 2024 | Olympic Games | Paris, France |
| 200m individual medley | 2:06.56 | | Summer McIntosh | Canada | 3 August 2024 | Olympic Games | Paris, France |
| 400m individual medley | 4:24.38 | WR | Summer McIntosh | Canada | 16 May 2024 | Canadian Trials | Toronto, Canada |
| 4 × 100m freestyle relay | 3:36.19 | | Taylor Ruck (53.63)Penny Oleksiak (53.70)Rebecca Smith (54.65)Kayla Sanchez (54.21) | Canada | 27 August 2017 | World Junior Championships | Indianapolis, United States |
| 4 × 200m freestyle relay | 7:51.47 | | Kayla Sanchez (1:59.01)Penny Oleksiak (1:56.86)Rebecca Smith (1:58.66)Taylor Ruck (1:56.94) | Canada | 23 August 2017 | World Junior Championships | Indianapolis, United States |
| 4 × 100m medley relay | 3:58.38 | | Jade Hannah (1:00.68)Faith Knelson (1:07.86)Penny Oleksiak (56.91)Taylor Ruck (52.93) | Canada | 28 August 2017 | World Junior Championships | Indianapolis, United States |

### Mixed

| Event | Time | Name | Nationality | Date | Meet | Location | Ref |
| 4 × 100 m freestyle relay | 3:24.29 | Flynn Southam (48.58)Edward Sommerville (48.54)Olivia Wunsch (53.62)Milla Jansen (53.55) | Australia | 6 September 2023 | World Junior Championships | Netanya, Israel | |
| 4 × 100 m medley relay | 3:44.84 | William Grant (53.89)Josh Matheny (59.31)Torri Huske (58.04)Gretchen Walsh (53.60) | United States | 21 August 2019 | World Junior Championships | Budapest, Hungary | |

## Short Course (25 m)
### Boys

| Event | Time | | Name | Nationality | Date | Meet | Location |
| 50m freestyle | 20.98 | | Kenzo Simons | Netherlands | 22 December 2019 | Dutch Championships | Tilburg, Netherlands |
| 50m freestyle | 20.70 | rh, not ratified, fastest all-time junior | Evgeny Sedov | Russia | 6 December 2014 | World Championships | Doha, Qatar |
| 100m freestyle | 45.64 | | David Popovici | Romania | 15 December 2022 | World Championships | Melbourne, Australia |
| 200m freestyle | 1:40.65 | AF | Matthew Sates | South Africa | 3 October 2021 | World Cup | Berlin, Germany |
| 200m freestyle | 1:40.08 | not ratified, fastest all-time junior | Danila Izotov | Russia | 13 December 2009 | European Championships | Istanbul, Turkey |
| 400m freestyle | 3:37.92 | | Matthew Sates | South Africa | 7 October 2021 | World Cup | Budapest, Hungary |
| 400m freestyle | 3:35.64 | not ratified, fastest all-time junior | Ian Thorpe | Australia | 2 April 1999 | World Championships | Hong Kong, Hong Kong |
| 800m freestyle | 7:36.00 | | Sven Schwarz | Germany | 16 November 2019 | German Championships | Berlin, Germany |
| 1500m freestyle | 14:20.64 | | Kuzey Tunçelli | Turkey | 10 December 2024 | World Championships | Budapest, Hungary |
| 1500m freestyle | 14:19.55 | not ratified, fastest all-time junior | Grant Hackett | Australia | 27 September 1998 | Australian Championships | Perth, Australia |
| 50m backstroke | 22.47 | | Miron Lifintsev | Russia | 13 December 2024 | World Championships | Budapest, Hungary |
| 100m backstroke | 48.76 | | Miron Lifintsev | Russia | 11 December 2024 | World Championships | Budapest, Hungary |
| 200m backstroke | 1:48.02 | | Kliment Kolesnikov | Russia | 13 December 2017 | European Championships | Copenhagen, Denmark |
| 50m breaststroke | 25.66 | sf | Chris Smith | South Africa | 14 December 2024 | World Championships | Budapest, Hungary |
| 100m breaststroke | 56.66 | | Simone Cerasuolo | Italy | 1 December 2021 | Italian Championships | Riccione, Italy |
| 200m breaststroke | 2:03.23 | | Akihiro Yamaguchi | Japan | 14 December 2012 | World Championships | Istanbul, Turkey |
| 50m butterfly | 22.28 | | Ilya Kharun | Canada | 14 December 2022 | World Championships | Melbourne, Australia |
| 100m butterfly | 49.03 | | Ilya Kharun | Canada | 18 December 2022 | World Championships | Melbourne, Australia |
| 200m butterfly | 1:49.61 | | Chen Juner | China | 28 October 2022 | Chinese Championships | Beijing, China |
| 100m individual medley | 50.63 | | Kliment Kolesnikov | Russia | 14 December 2018 | World Championships | Hangzhou, China |
| 200m individual medley | 1:51.45 | | Matthew Sates | South Africa | 2 October 2021 | World Cup | Berlin, Germany |
| 400m individual medley | 3:56.47 | ER | Ilya Borodin | Russia | 20 December 2021 | World Championships | Kazan, Russia |
| 4×50m freestyle relay | 1:27.46 | | | | | |
| 4 × 100m freestyle relay | 3:12.56 | | | | | |
| 4 × 200m freestyle relay | 6:59.66 | | | | | |
| 4×50m medley relay | 1:38.29 | | | | | |
| 4 × 100m medley relay | 3:28.05 | | | | | |

### Girls

| Event | Time | | Name | Nationality | Date | Meet | Location |
| 50m freestyle | 23.66 | | Eva Okaro | Great Britain | 15 December 2024 | World Championships | Budapest, Hungary |
| 100m freestyle | 51.45 | | Kayla Sanchez | Canada | 14 December 2018 | Swim England Winter Championships | Sheffield, United Kingdom |
| 200m freestyle | 1:51.62 | | Claire Weinstein | United States | 15 December 2024 | World Championships | Budapest, Hungary |
| 200m freestyle | 1:51.38 | OC, not ratified, fastest all-time junior | Ariarne Titmus | Australia | 11 December 2018 | World Championships | Hangzhou, China |
| 400m freestyle | 3:50.25 | WR | Summer McIntosh | Canada | 10 December 2024 | World Championships | Budapest, Hungary |
| 800m freestyle | 7:59.44 | AS | Wang Jianjiahe | China | 6 October 2018 | World Cup | Budapest, Hungary |
| 1500m freestyle | 15:42.05 | | Katie Grimes | United States | 4 November 2022 | World Cup | Indianapolis, United States |
| 50m backstroke | 26.03 | sf | Sara Curtis | Italy | 12 December 2024 | World Championships | Budapest, Hungary |
| 50m backstroke | 25.49 | not ratified, fastest all-time junior | Mollie O'Callaghan | Australia | 14 December 2022 | World Championships | Melbourne, Australia |
| 100m backstroke | 55.75 | | Bella Sims | United States | 4 November 2022 | World Cup | Indianapolis, United States |
| 100m backstroke | 55.62 | not ratified, fastest all-time junior | Mollie O'Callaghan | Australia | 17 December 2022 | World Championships | Melbourne, Australia |
| 200m backstroke | 1:59.96 | | Summer McIntosh | Canada | 15 December 2024 | World Championships | Budapest, Hungary |
| 50m breaststroke | 28.81 | | Benedetta Pilato | Italy | 21 November 2020 | International Swimming League | Budapest, Hungary |
| 50m breaststroke | 28.81 | not ratified | Ruta Meilutyte | Lithuania | 3 December 2014 | World Championships | Doha, Qatar |
| 100m breaststroke | 1:02.36 | =WR | Ruta Meilutyte | Lithuania | 12 October 2013 | World Cup | Moscow, Russia |
| 200m breaststroke | 2:14.70 | | Evgeniia Chikunova | Russia | 25 November 2022 | Solidarity Games | Kazan, Russia |
| 50m butterfly | 24.55 | | Claire Curzan | United States | 19 December 2021 | World Championships | Abu Dhabi, United Arab Emirates |
| 100m butterfly | 55.39 | | Claire Curzan | United States | 21 December 2021 | World Championships | Abu Dhabi, United Arab Emirates |
| 100m butterfly | 55.10 | AS, # | Mizuki Hirai | Japan | 22 February 2025 | Sagamihara City Championships | Sagamihara, Japan |
| 200m butterfly | 1:59.32 | WR | Summer McIntosh | Canada | 12 December 2024 | World Championships | Budapest, Hungary |
| 100m individual medley | 57.59 | | Anastasiya Shkurdai | Belarus | 22 November 2020 | International Swimming League | Budapest, Hungary |
| 200m individual medley | 2:04.48 | | Yu Yiting | China | 20 December 2021 | World Championships | Abu Dhabi, United Arab Emirates |
| 400m individual medley | 4:15.48 | WR | Summer McIntosh | Canada | 14 December 2024 | World Championships | Budapest, Hungary |
| 4×50m freestyle relay | 1:40.59 | | | | | |
| 4 × 100m freestyle relay | 3:32.63 | | | | | |
| 4 × 200m freestyle relay | 7:43.73 | | | | | |
| 4×50m medley relay | 1:44.43 | not ratified | Wan Letian (26.42)Tang Qianting (28.96)Yu Yiting (25.28)Cheng Yujie (23.78) | China | 17 December 2021 | World Championships | Abu Dhabi, United Arab Emirates |
| 4 × 100m medley relay | 3:49.16 | | | | | |

### Mixed

| Event | Time | | Name | Nationality | Date | Meet | Location |
| 4×50m freestyle relay | 1:31.50 | not ratified | Daniel Diehl (22.07)Quintin McCarty (21.35)Kristina Paegle (23.78)Carly Novelline (24.30) | United States | 2 October 2021 | World Cup | Berlin, Germany |
| 4×50m freestyle relay | 1:31.23 | not ratified | Jacob Mills (22.22)Nicholas Finch (21.61)Skye Carter (23.98)Eva Okaro (23.42) | Great Britain | 14 December 2023 | Ontario Junior International | Toronto, Canada |
| 4×50m medley relay | 1:41.21 | | Quintin McCarty (24.07)Zhier Fan (26.75)Charlotte Hook (26.27)Kristina Paegle (24.12) | United States | 9 October 2021 | World Cup | Budapest, Hungary |