The 3rd FINA World Junior Swimming Championships, were held on August 16–21, 2011, in Lima, Peru.
| Boys' freestyle | |||||||
| 50 m | Cameron McEvoy | 22.69 | Aitor Martinez Rodriguez | 22.72 | Kristian Golomeev | 22.80 | |
| 100 m | Cameron McEvoy | 50.16 | Dmitry Yermakov Pawel Werner | 50.46 | |||
| 200 m | Chad Bobrosky | 1:49.13 | Pawel Werner | 1:49.39 | Cameron McEvoy | 1:50.12 | |
| 400 m | Fumiya Hidaka | 3:50.97 CR | Chad Bobrosky | 3:51.46 | Evan Pinion | 3:51.47 | |
| 800 m | Evan Pinion | 7:55.92 CR | Gabriele Detti | 8:00.22 | Gregorio Paltrinieri | 8:02.06 | |
| 1500 m | Evan Pinion | 15:11.03 CR | Gregorio Paltrinieri | 15:15.02 | Gabriele Detti | 15:18.46 | |
| Boys' backstroke | |||||||
| 50 m | Christian Diener | 25.59 | Jacob Pebley | 25.75 | Niccolò Bonacchi | 25.78 | |
| 100 m | Jacob Pebley | 55.01 | Fabio Laugeni | 55.68 | Kosuke Hagino | 55.69 | |
| 200 m | Jacob Pebley | 1:58.73 CR | Kosuke Hagino | 1:58.94 | Ryan Murphy | 1:59.63 | |
| Boys' breaststroke | |||||||
| 50 m | Panagiotis Samilidis | 28.27 | Akihiro Yamaguchi Craig Benson | 28.44 | |||
| 100 m | Craig Benson | 1:01.34 CR | Akihiro Yamaguchi | 1:01.54 | Panagiotis Samilidis | 1:01.64 | |
| 200 m | Akihiro Yamaguchi | 2:11.70 CR | Oleksiy Rozhkov | 2:13.94 | Maksym Shemberev | 2:14.08 | |
| Boys' butterfly | |||||||
| 50 m | Maclin Davis | 24.26 | Mihael Vukic | 24.30 | Martino Lucatello | 24.54 | |
| 100 m | Maclin Davis | 53.24 | Kenta Hirai | 53.40 | Arthur Mendes | 53.96 | |
| 200 m | Kenta Hirai | 1:57.16 CR | Andreas Vazaios | 1:59.27 | Mackenzie Darragh | 1:59.31 | |
| Boys' individual medley | |||||||
| 200 m | Kosuke Hagino | 2:00.90 CR | Andreas Vazaios | 2:01.64 | Maksym Shemberev | 2:02.37 | |
| 400 m | Maksym Shemberev | 4:15.64 CR | Li Xiang | 4:17.00 | Kosuke Hagino | 4:17.15 | |
| Boys' relays | |||||||
| 4×100 m freestyle | Matt Ellis (50.83) Allen Browning (50.49) Kyle Darmody (50.15) Seth Stubblefield (49.63) | 3:21.10 | Luke Peddie (50.76) Alec Page (51.40) Omar Arafa (49.86) Chad Bobrosky (49.66) | 3:21.68 | Nikita Kitaev (51.62) Dmitri Kuleshov (51.11) Aleksandr Klyukin (50.34) Dmitry Yermakov (49.66) | 3:22.73 | |
| 4×200 m freestyle | Alec Page (1:51.64) Keegan Zanatta (1:51.16) Omar Arafa (1:51.20) Chad Bobrosky (1:48.95) | 7:22.95 | Qiu Yinghua (1:51.97) Pu Wenjie (1:50.20) Li Xiang (1:50.65) Mao Feilian (1:50.46) | 7:23.28 | Pawel Werner Filip Bujoczek Michal Poprawa (1:52.19) Radoslaw Bor (1:51.19) | 7:24.09 | |
| 4×100 m medley | Jacob Pebley (55.06) Nicolas Fink (1:02.16) Maclin Davis (52.44) Seth Stubblefield (49.99) | 3:39.65 CR | Kosuke Hagino (55.67) Akihiro Yamaguchi (1:00.56) Kenta Hirai (52.99) Fumiya Hidaka (50.70) | 3:39.92 | Fabio Laugeni (56.15) Flavio Bizzarri (1:03.17) Martino Lucatello (53.68) Giacomo Ferri (49.44) | 3:42.44 | |
| Girls' freestyle | |||||||
| 50 m | Bronte Campbell | 25.22 CR | Lia Neal | 25.30 | Chantal Van Landeghem | 25.35 | |
| 100 m | Lia Neal | 54.90 CR | Chantal Van Landeghem | 55.29 | Bronte Campbell | 55.46 | |
| 200 m | Brittany MacLean | 1:58.93 CR | Chelsea Chenault | 1:59.69 | Fu Yuanhui | 1:59.70 | |
| 400 m | Brittany MacLean | 4:10.32 | Bonnie Macdonald | 4:11.86 | Gillian Ryan | 4:12.28 | |
| 800 m | Bonnie Macdonald | 8:32.30 CR | Gillian Ryan | 8:33.46 | Claudia Dasca | 8:34.29 | |
| 1500 m | Tjasa Oder | 16:18.63 CR | Rachel Zilinskas | 16:18.85 | Claudia Dasca | 16:24.30 | |
| Girls' backstroke | |||||||
| 50 m | Daryna Zevina | 28.45 CR | Emma Saunders | 28.76 | Chantal Van Landeghem | 29.01 | |
| 100 m | Daryna Zevina | 1:00.59 CR | Fu Yuanhui | 1:01.13 | Emma Saunders | 1:02.35 | |
| 200 m | Daryna Zevina | 2:10.43 CR | Miyu Otsuka | 2:11.02 | Karley Mann | 2:11.40 | |
| Girls' breaststroke | |||||||
| 50 m | Lisa Fissneider | 31.51 | Sarah Haase | 31.84 | Claire Polit | 31.95 | |
| 100 m | Lisa Fissneider | 1:07.71 CR | Kanako Watanabe | 1:08.89 | Irina Novikova | 1:09.10 | |
| 200 m | Kanako Watanabe | 2:25.52 | Lisa Fissneider | 2:26.01 | Irina Novikova | 2:26.04 | |
| Girls' butterfly | |||||||
| 50 m | Farida Osman | 26.69 CR | Kendyl Stewart | 26.78 | Vanessa Mohr Chantal Van Landeghem | 26.85 | |
| 100 m | Rachael Kelly | 59.37 CR | Rino Hosoda | 59.39 | Alexandra Wenk | 59.64 | |
| 200 m | Judit Ignacio Sorribes | 2:08.25 | Alessia Polieri | 2:09.65 | Miyu Otsuka | 2:11.35 | |
| Girls' individual medley | |||||||
| 200 m | Beatriz Gomez Cortes | 2:13.57 | Emu Higuchi | 2:13.96 | Erika Seltenreich-Hodgson | 2:15.62 | |
| 400 m | Miyu Otsuka | 4:40.98 CR | Alessia Polieri | 4:43.41 | Claudia Dasca | 4:43.53 | |
| Girls' relays | |||||||
| 4×100 m freestyle | Kristen Vredeveld (55.64) Simone Manuel (55.90) Rachel Acker (56.48) Lia Neal (54.83) | 3:42.85 CR | Brittany MacLean (55.65) Victoria Chan (57.27) Lauren Earp (55.63) Chantal Van Landeghem (54.69) | 3:43.24 | Amelia Maughan (57.03) Emma Saunders (55.99) Emily Jones (57.70) Jessica Lloyd (55.27) | 3:45.99 | |
| 4×200 m freestyle | Julia Anderson (2:00.10) Lia Neal (1:59.41) Gillian Ryan (2:00.98) Chelsea Chenault (1:59.84) | 8:00.33 CR | Lauren Earp (2:01.37) Victoria Chan (2:03.07) Tabitha Baumann (2:03.43) Brittany MacLean (1:57.05) | 8:04.92 | Bonnie Macdonald (2:00.23) Brianna Throssell (2:02.24) Taylor McKeown (2:03.61) Mikkayla Sheridan (2:00.60) | 8:06.68 | |
| 4×100 m medley | Yukiko Watanabe (1:02.91) Kanako Watanabe (1:08.32) Rino Hosoda (59.44) Mao Kawakami (54.98) | 4:05.65 CR | Kylie Stewart (1:02.46) KC Moss (1:11.73) Kendyl Stewart (58.76) Lia Neal (54.84) | 4:07.79 | Julia Larina (1:03.00) Irina Novikova (1:09.10) Daria Tcvetkova (59.86) Veria Kolotushkina (56.03) | 4:07.99 | |