The swimming competitions at the 2012 Summer Olympics in London took place from 28 July to 4 August at the Aquatics Centre. The open-water competition took place from 9 to 10 August in Hyde Park.

Swimming featured 32 events (16 male, 16 female), contested in a 50 m long course pool within the Olympic Park.

The United States claimed a total of 30 medals (16 golds, 8 silver, and 6 bronze) in the leaderboard to maintain its supremacy as the most successful nation in swimming. Brought by an unprecedented sporting domination, Michael Phelps emerged as the most decorated Olympian of all time after winning six more medals at these Games to bring his total after the 2012 games to 22 (18 golds, 2 silver, and 2 bronze). Battling against the Americans for an overall medal count, China mounted to an unexpected second-place effort on the leaderboard with a tally of 10 medals (five golds, three silver, and bronze) after striking a superb double from Sun Yang in long-distance freestyle (both 400 and 1500 m) and Ye Shiwen in the individual medley (both 200 and 400 m). Meanwhile, France ended on a spectacular fashion in third spot with a total of seven medals (four golds, two silver, and one bronze), followed by the Netherlands with four, including two golds from Ranomi Kromowidjojo in sprint freestyle (both 50 and 100 m), and South Africa with three.

For the first time since 1992, Australia delivered an underwhelming performance with only a single triumph in the freestyle relay, but managed to bring home a total of ten medals. After not winning a gold in swimming since 2000, Japan produced the most medals in the post-war era to build a tally of eleven (three silver and eight bronze).

A total of nine world records and twenty five Olympic records were set during the competition.

Events

Similar to the program's format in 2008, swimming featured a total of 32 events (16 each for men and women). The following events were contested (all pool events were long course, and distances are in metres unless stated): Freestyle: 50, 100, 200, 400, 800 (women), and 1500 (men); Backstroke: 100 and 200; Breaststroke: 100 and 200; Butterfly: 100 and 200; Individual medley: 200 and 400; Relays: 4 × 100 free, 4 × 200 free; 4 × 100 medley

Schedule Similar to the previous Olympics since 2000, with the exception of 2008, swimming program schedule occurred in two segments. The prelims were held in the morning, with semifinals and final in the following evening session.

+Men Date → 28 Jul 29 Jul 30 Jul 31 Jul 1 Aug 2 Aug 3 Aug 4 AugEvent ↓ M E M E M E M E M E M E M E M E50 m freestyle H ½ F 100 m freestyle H ½ F 200 m freestyle H ½ F 400 m freestyle HF 1500 m freestyle H F 100 m backstroke H ½ F 200 m backstroke H ½ F 100 m breaststroke H ½ F 200 m breaststroke H ½ F 100 m butterfly H ½ F 200 m butterfly H ½ F 200 m individual medley H ½ F 400 m individual medley HF freestyle relay HF freestyle relay HF medley relay H F +Women Date → 28 Jul 29 Jul 30 Jul 31 Jul 1 Aug 2 Aug 3 Aug 4 AugEvent ↓ M E M E M E M E M E M E M E M E50 m freestyle H ½ F 100 m freestyle H ½ F 200 m freestyle H ½ F 400 m freestyle HF 800 m freestyle H F100 m backstroke H ½ F 200 m backstroke H ½ F 100 m breaststroke H ½ F 200 m breaststroke H ½ F 100 m butterfly H ½ F 200 m butterfly H ½ F 200 m individual medley H ½ F 400 m individual medley HF freestyle relay HF freestyle relay HF medley relay H F

Qualification

FINA By-Law BL 9.3.6.4 lays out the qualification procedures for the "Swimming" competition at the Olympics. Each country is allowed to enter up to two swimmers per individual event (provided they qualify), and one entry per relay; and a country may not have more than 26 males and 26 females (52 total) on its team.

Individual events On 11 November 2010, FINA posted the qualifying times for individual events for the 2012 Olympics. The time standards consist of two time standards, an "Olympic Qualifying Time" and an "Olympic invitation time". Each country was able to enter up to two swimmers per event, provided both swimmers met the (faster) qualifying time. A country was able to enter one swimmer per event that met the invitation standard. Any swimmer who met the "qualifying" time was entered in the event for the Games; a swimmer meeting the "invitation" standard was eligible for entry, and their entry was allotted/filled in by ranking.

If a country has no swimmers meeting either qualifying standard, it may enter one male and one female. A country that does not receive an allocation spot but has at least one swimmer who meets a qualifying standard may enter the swimmer with the highest ranking.

Relay events Each relay event featured 16 teams, composed of: 12: the top-12 finishers at the 2011 World Championships in each relay event. 4: the 4 fastest non-qualified teams, based on times in the 15-months preceding the Olympics.

Participating nations FINA announced in early July 2012 that 631 athletes from 166 nations would compete in swimming events at the 2012 Olympics. 59 nations qualified via the A cut (OQT), 12 via the B cut (OST) and 95 via Universality. Brunei, Central African Republic, Djibouti, Ethiopia, Lesotho, Liechtenstein, Togo, and Tonga made their official debut in swimming. Meanwhile, Grenada, Iraq, and Saint Vincent and the Grenadines returned to the sport after an eight-year absence. Nations with swimmers at the Games are (team size in parentheses):

Medal table

Note: There were ties for silver in the men's 200 m freestyle and men's 100 m butterfly events.

Results

Men's events 50 m freestyle 21.34 21.54 21.59 100 m freestyle 47.52 47.53 47.80 200 m freestyle 1:43.14 NR 1:44.93 NR 1:44.93Not awardedas there was a tie for silver. 400 m freestyle 3:40.14 , AS 3:42.06 3:44.69 1500 m freestyle 14:31.02 14:39.63 AM 14:40.31 100 m backstroke 52.16 52.92 52.97 200 m backstroke 1:53.41 1:53.78 1:53.94 100 m breaststroke58.46 58.9359.49 200 m breaststroke 2:07.28 2:07.43 NR 2:08.29 100 m butterfly 51.21 51.44Not awardedas there was a tie for silver. 200 m butterfly 1:52.96 AF 1:53.01 1:53.21 200 m individual medley 1:54.27 1:54.90 1:56.22 400 m individual medley 4:05.18 4:08.86 =SA 4:08.94 AS 4 × 100 m freestyle relayAmaury Leveaux (48.13)Fabien Gilot (47.67)Clément Lefert (47.39)Yannick Agnel (46.74)Alain BernardJérémy Stravius 3:09.93Nathan Adrian (47.89)Michael Phelps (47.15)Cullen Jones (47.60)Ryan Lochte (47.74)Jimmy FeigenMatt GreversRicky BerensJason Lezak 3:10.38Andrey Grechin (48.57)Nikita Lobintsev (47.39)Vladimir Morozov (47.85)Danila Izotov (47.60)Yevgeny LagunovSergey Fesikov 3:11.41 4 × 200 m freestyle relayRyan Lochte (1:45.15)Conor Dwyer (1:45.23)Ricky Berens (1:45.27)Michael Phelps (1:44.05)Charlie HouchinMatt McLeanDavis Tarwater6:59.70Amaury Leveaux (1:46.70)Grégory Mallet (1:46.83)Clément Lefert (1:46.00)Yannick Agnel (1:43.24)Jérémy Stravius7:02.77 NRHao Yun (1:47.12)Li Yunqi (1:46.46)Jiang Haiqi (1:47.17)Sun Yang (1:45.55)Lü ZhiwuDai Jun7:06.30 4 × 100 m medley relayMatt Grevers (52.58)Brendan Hansen (59.19)Michael Phelps (50.73)Nathan Adrian (46.85)Nick ThomanEric ShanteauTyler McGillCullen Jones3:29.35Ryosuke Irie (52.92)Kosuke Kitajima (58.64)Takeshi Matsuda (51.20)Takuro Fujii (48.50)3:31.26Hayden Stoeckel (53.71)Christian Sprenger (59.05)Matt Targett (51.60)James Magnussen (47.22)Brenton RickardTommaso D'Orsogna3:31.58 Swimmers who participated in the heats only and received medals.

Women's events 50 m freestyle 24.05 24.28 NR 24.39 100 m freestyle 53.00 53.38 NR 53.44 200 m freestyle 1:53.61 , AM 1:55.58 1:55.81 400 m freestyle 4:01.45 4:01.77 AM 4:03.01 800 m freestyle 8:14.63 AM 8:18.76 NR 8:20.32 100 m backstroke 58.33 AM 58.68 58.83 AS 200 m backstroke 2:04.06 2:05.92 2:06.55 100 m breaststroke 1:05.47 1:05.55 1:06.46 200 m breaststroke 2:19.59 2:20.72 =AS 2:20.92 ER 100 m butterfly55.98 56.87 56.94 200 m butterfly2:04.06 2:05.25 NR2:05.48 200 m individual medley 2:07.57 , AS 2:08.15 2:08.95 400 m individual medley 4:28.43 4:31.27 4:32.91 4 × 100 m freestyle relayAlicia Coutts (53.90)Cate Campbell (53.19)Brittany Elmslie (53.41)Melanie Schlanger (52.65)Emily SeebohmYolane KuklaLibby Trickett3:33.15 Inge Dekker (54.67)Marleen Veldhuis (53.80)Femke Heemskerk (53.39)Ranomi Kromowidjojo (51.93)Hinkelien Schreuder3:33.79Missy Franklin (53.52)Jessica Hardy (53.53)Lia Neal (53.65)Allison Schmitt (53.54)Amanda WeirNatalie Coughlin3:34.24 AM 4 × 200 m freestyle relayMissy Franklin (1:55.96)Dana Vollmer (1:56.02)Shannon Vreeland (1:56.85)Allison Schmitt (1:54.09)Lauren PerdueAlyssa Anderson7:42.92 Bronte Barratt (1:55.76)Melanie Schlanger (1:55.62)Kylie Palmer (1:56.91)Alicia Coutts (1:56.12)Brittany ElmslieAngie BainbridgeJade NeilsenBlair Evans7:44.41Camille Muffat (1:55.51)Charlotte Bonnet (1:57.78)Ophélie-Cyrielle Étienne (1:58.05)Coralie Balmy (1:56.15)Margaux FarrellMylène Lazare7:47.49 NR 4 × 100 m medley relayMissy Franklin (58.50)Rebecca Soni (1:04.82)Dana Vollmer (55.48)Allison Schmitt (53.25)Rachel BootsmaBreeja LarsonClaire DonahueJessica Hardy3:52.05 Emily Seebohm (59.01)Leisel Jones (1:06.06)Alicia Coutts (56.41)Melanie Schlanger (52.54)Brittany Elmslie3:54.02Aya Terakawa (58.99)Satomi Suzuki (1:05.96)Yuka Kato (57.36)Haruka Ueda (53.42)3:55.73 Swimmers who participated in the heats only and received medals.

Olympic and world records broken

Men Event Date Round Name Nationality Time Record DayMen's 400 m freestyle 28 July Final Sun Yang 3:40.14 OR 1Men's 100 m breaststroke 28 July Semifinal Cameron van der Burgh 58.83 OR 1Men's 100 m breaststroke 29 July Final Cameron van der Burgh 58.46 WR 2Men's 100 m backstroke 30 July Final Matt Grevers 52.16 OR 3Men's 200 m breaststroke 1 August Final Dániel Gyurta 2:07.28WR 5Men's 200 m backstroke 2 August Final Tyler Clary 1:53.41OR 6Men's 1500 m freestyle 4 August Final Sun Yang 14:31.02 WR 8

Women Event Date Round Name Nationality Time Record DayWomen's 100 m butterfly 28 July Heats Dana Vollmer 56.25 OR 1Women's 400 m individual medley 28 July Final Ye Shiwen 4:28.43 WR 1Women's 4 × 100 m freestyle relay 28 July Final Alicia Coutts (53.90) Cate Campbell (53.19) Brittany Elmslie (53.41) Melanie Schlanger (52.65) 3:33.15 OR 1Women's 100 m backstroke 29 July Heats Emily Seebohm 58.23 OR 2Women's 100 m butterfly 29 July Final Dana Vollmer 55.98 WR 2Women's 400 m freestyle 29 July Final Camille Muffat 4:01.45OR 2Women's 200 m individual medley 30 July Semifinal Ye Shiwen 2:08.39 OR 3Women's 200 m freestyle 31 July Final Allison Schmitt 1:53.61 OR 4Women's 200 m individual medley 31 July Final Ye Shiwen 2:07.57 OR 4Women's 100 m freestyle 1 August Semifinal Ranomi Kromowidjojo 53.05 OR 5Women's 200 m butterfly 1 August Final Jiao Liuyang 2:04.06 OR 5Women's 200 m breaststroke 1 August Semifinal Rebecca Soni 2:20.00 WR 5Women's 4 × 200 m freestyle relay 1 August Final Missy Franklin (1:55.96) Dana Vollmer (1:56.02) Shannon Vreeland (1:56.85) Allison Schmitt (1:54.09) 7:42.92 OR 5Women's 200 m breaststroke 2 August Final Rebecca Soni 2:19.59 WR 6Women's 100 m freestyle 2 August Final Ranomi Kromowidjojo 53.00 OR 6Women's 200 m backstroke 3 August Final Missy Franklin 2:04.06 WR 7Women's 50 m freestyle 4 August Final Ranomi Kromowidjojo 24.05 OR 8Women's 4 × 100 m medley relay 4 August Final Missy Franklin (58.50) Rebecca Soni (1:04.82) Dana Vollmer (55.48) Allison Schmitt (53.25) 3:52.05 WR 8

All world records (WR) are subsequently Olympic records (OR).

Derya Büyükuncu and Lars Frölander were the first swimmers to participate in six consecutive Olympic Games (1992-2012).

Controversies In the women's 400-metre individual medley, Chinese Ye Shiwen won in a world-record time of 4:28.43. After the race, Ye had allegations against her suggesting the use of drugs that drew comment from the International Olympic Committee and FINA who defended Ye. Ye has never tested positive of any performance-enhancing drugs. Some claim the accusations were a result of xenophobia towards the Chinese.