“I am so shocked I can't believe it. I'm going to savour the moment.”Jessica Ennis
The rowers started the celebrations with gold in the men's four and the women's lightweight double sculls.
The women's team pursuiters added track cycling gold in the London Velodrome.
Then Jessica Ennis, Greg Rutherford and Mo Farah capped a historic day by winning the heptathlon, long jump and 10,000m at a jubilant Olympic Stadium.
Saturday's stunning series of successes keep the host nation third in the medals table with 14 golds, behind the United States and China.
Britain has now won 29 medals overall, having also taken seven silvers and eight bronzes at these Games.Play media
Ennis had dominated the heptathlon from the start, leading her rivals after the four events on day one.
She then effectively clinched gold with strong performances in the long jump and javelin on day two, before rounding off victory in the 800m.
Her time of two minutes 8.65 seconds meant she smashed her own British record for the heptathlon, finishing the seven-event competition with 6,955 points, 49 more than she scored in Gotzis in May.
"I am so shocked I can't believe it," said Ennis. "I'm going to savour the moment. I've had great support, although I've been under a huge amount of pressure."
Russia's world champion Tatyana Chernova took silver, with Ukraine's Lyudmyla Yosypenko finishing with the bronze.
Rutherford took gold in the long jump with a fourth-round leap of 8.31m, equalling the feat of Lynn Davies in 1964.Continue reading the main story
“It's never going to get any better than this. It's the best moment of my life.”Mo Farah
Davies had been the only British man to have won an Olympic medal in the event, taking gold in Tokyo.
"What a night for British athletics," Rutherford told BBC Sport. "Three gold medals. It's absolutely incredible."
Farah followed Rutherford's success by controlling the 10,000m from start to finish.
"I just can't believe it," said Farah, who could also go for 5,000m gold. "The crowd got behind me so much and it was getting louder and louder.
"I've not experienced anything like this. It's never going to get any better than this. It's the best moment of my life."
The wins for Ennis, Rutherford and Farah created history for Britain. Never before had they won three gold medals in a single athletics session at at Olympics.
Britain's first gold of the day came at Eton Dorney as the men's four of Andy Triggs Hodge, Pete Reed, Andy Gregory and Tom James led from the start to triumph.
Just 20 minutes later, the women's lightweight double sculls team of Sophie Hosking and Katherine Copeland did the same, before the men's lightweight double sculls duo of Zac Purchase and Mark Hunter then finished second following a restart after their seat broke.Play media
Britain have won a total of four rowing golds, with two silvers and three bronzes, to set a new record for an Olympic regatta.
Copeland said: "I can't believe this is real. We've just won the Olympics. I've been trying all week not to think about it because it has been making me cry."
Hosking added: "It's something we have been working on for so long."
On the men's four victory, Triggs Hodge said: "It was our masterpiece. Four years we have worked on that."
Laura Trott, Dani King and Jo Rowsell crushed the United States to win the team pursuit. They claimed victory in a time of 3:14.051 to set their sixth successive world record.Continue reading the main story
“I can't believe it. It's been my dream since I was eight.”Laura Trott
"It's mad," said Trott. "I can't believe it. It's been my dream since I was eight. We've gone and done it. I don't think we expected it."
Rowsell added: "I could tell we'd done it by the cheer of the crowd."
In the tennis, Andy Murray guaranteed himself another silver medal by reaching the mixed doubles final with playing partner Laura Robson.
The Scot is already through to Sunday men's singles final, where he will play Roger Federer.
They beat Germany's Christopher Kas and Sabine Lisicki in the last match on Court One at Wimbledon.
Back on the athletics track, defending champion Usain Bolt reached the semi-finals of the 100m, winning his heat in 10.09 seconds.
American Ryan Bailey qualified fastest in 9.88, with world champion Yohan Blake running 10.00.
British hope Adam Gemili, who was playing non-league football as recently as January, also qualified in 10.11, behind Jamaica's Asafa Powell, who ran 10.04. Briton Dwain Chambers is through in 10.02.