Team GB's Rebecca Adlington has won the first medal in the pool with a bronze in the 400m freestyle.
The event was won by France's Camille Muffat but the British and Olympic champion succeeded in holding on to third place. Silver was won by US swimmer Allison Schmitt.
Adlington will be boosted by her performance has she prepares for her next race in the 800m freestyle, which is a her preferred distance.
The 23-year-old told BBC Sport that competing in front of a largely British audience within the Aquatics Centre was amazing.
"The crowd was so overwhelming. Twelve years' hard work has gone into that," said Adlington.
"Four hundred metres always feel so hard for me and they were so far ahead. I'm so glad I've got a medal at a home Games. Not many people can say that."
Meanwhile, there was success for the men's Team GB football squad against the United Arab Emirates. Playing at Wembley Stadium, the home nation secured a 3-1 victory, which means that the team only needs a draw against Uruguay in their final group game to go through to the quarter-finals.
The women's hockey competition also saw a win from Team GB as they performed well against Japan in strong performance which resulted in a 4-0 victory.
Player Alex Danson said: "To come out and win our first game was exactly what we dreamed of and have worked towards."
Great Britain will now play South Korea in the second group match on August 1st at the Olympic Park.
There are thousands of events happening across London during the Olympics ranging from sport-related to art projects making sure there is something for everyone enjoying stays in central London hotels over the next two weeks.