Karl Gunnar Larsson is a former swimmer from Sweden. He won the 400 metre individual medley event at the 1972 Summer Olympics by two one-thousandths (0.002) of a second over American Tim McKee, breaking the Olympic record. The controversy over the accuracy of such timing was the reason the international swimming rules were subsequently changed, and today swimming times are measured in hundredths of a second.

The 1972 Summer Olympics were held in Munich, West Germany, 29 events in swimming were contested. There was a total of 532 participants from 52 countries competing.