For the swimming competitions at the 2012 Summer Olympics the following qualification systems were in place.
A National Olympic Committee (NOC) may enter up to 2 qualified athletes in each individual event if both meet the Olympic Qualifying Time (OQT).
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.
[2][3] Named swimmers have qualified personally through national selection meets or have been nominated by their National Olympic Committee (NOC).
The result is here: * Chris Walker-Hebborn qualified in this event by an allocated quota, following a sudden withdrawal of Israel's Jonatan Kopelev.