For the swimming competitions at the 2012 Summer Olympics the following qualification systems were in place. The list has been updated to 20 August 2011. Qualification ends on 3 July 2012.
Qualifying standards
A National Olympic Committee (NOC) may enter up to 2 qualified athletes in each individual event if both meet the Olympic Qualifying Time (OQT). 1 athlete per event can potentially qualify should they meet the Olympic Selection Time (OST) and if the quota of 900 athletes has not been met. NOCs may enter swimmers regardless of time (1 swimmer per sex) if they have no swimmers meeting either standard entry time.
The qualifying time standards must be obtained in Continental Championships, National Olympic Trials or International Competitions approved by FINA in the period 1 March 2011 to 3 July 2012.
FINA qualifying standards are as follows:
Individual events
Only those with the Olympic Qualifying Time (OQT) are listed below as on the FINA website as those with the Olympic Selection Time are not guaranteed a place in the Olympic Games. Named swimmers have qualified personally through national selection meets or have been nominated by their National Olympic Committee (NOC).
The result is here: 438 – OQT (59 NF/NOCs) 181 – OST (12 NF/NOCs) – some still to be confirmed 131 – Relay-only swimmers 150 – Universality (95 NF/NOCs) Total: 900 (166 NF/NOCs)
Men's individual events
Men's 50 m freestyle
Men's 100 m freestyle
Men's 200 m freestyle
Men's 400 m freestyle
Men's 1500 m freestyle
Men's 100 m backstroke
* Chris Walker-Hebborn qualified in this event by an allocated quota, following a sudden withdrawal of Israel's Jonatan Kopelev.
Men's 200 m backstroke
Men's 100 m breaststroke
Men's 200 m breaststroke
Men's 100 m butterfly
Men's 200 m butterfly
Men's 200 m individual medley
Men's 400 m individual medley
* to be confirmed by NF/NOC
Women's individual events
Women's 50 m freestyle
Women's 100 m freestyle
Women's 200 m freestyle
Women's 400 m freestyle
Women's 800 m freestyle
Women's 100 m backstroke
Women's 200 m backstroke
Women's 100 m breaststroke
Women's 200 m breaststroke
Women's 100 m butterfly
Women's 200 m butterfly
Women's 200 m individual medley
Women's 400 m individual medley
* to be confirmed by NF/NOC
Relay events
Men's relay events
Men's 4 × 100 m freestyle relay
Men's 4 × 200 m freestyle relay
Men's 4 × 100 m medley relay
Women's relay events
Women's 4 × 100 m freestyle relay
Women's 4 × 200 m freestyle relay
Women's 4 × 100 m medley relay
Open water events
Men's 10 km marathon
Women's 10 km marathon
* If not qualified by any means. If Great Britain has already qualified quota will be added to the 2012 Olympic Marathon Swim Qualifier.