World and Olympic records set at the 2008 Summer Olympics metres butterfly, both set in Sydney, remained Olympic records. Michael Phelps of the United States also broke the record for the most gold medals ever won by an Olympian with a total of 14; 8 of which were won during the 2008 Summer Olympics - this was also a world record. <nowiki>*</nowiki> World record split from the 4 × 100 m freestyle relay Note: At the 4 × 100 m freestyle relay final, anchor Jason Lezak swam the fastest 100 m split (46.06); however, this is not considered an official FINA record, as he did not swim the first leg.
Azerbaijan at the 2012 Summer Olympics bearer at the opening ceremony. Azerbaijan left London with a total of 10 medals (2 gold, 2 silver, and 6 bronze), which doubled the nation's overall medal count at the 2004 Summer Olympics in Athens. This was also the nation's most successful Olympics, winning the largest number of medals received at a single games. More than half of these medals were awarded in wrestling, including gold medals won by Toghrul Asgarov and Sharif Sharifov from the men's freestyle events. Azerbaijan sent two swimmers to the London games, by Universality places. Butterfly swimmer Yevgeniy Lazuka previously competed under Belarus in Beijing.