The 32-year-old claimed his fourth Olympic Games gold and seventh medal in all, surpassing Sir Steve Redgrave with a British record haul of Games medals, in an imperious victory.
Wiggins was the penultimate of 37 riders to take to the course and completed the 44km route in 50:39.54 to triumph by 42 seconds, with fellow Briton Chris Froome third in 51:47.87.
World champion Tony Martin of Germany clocked 51:21.54 to claim silver.
Wiggins, who is from London, said: 'It's been an amazing six weeks.
'This was the plan. I've answered all the questions in the last six weeks.
'We've done it. To win another Olympic title in another event, it's never, ever going to get any better than that.'
In the women's event, Kristin Armstrong retained her title and promptly announced her retirement.
The 38-year-old from the United States finished the 29km route in 37:34.82 to win a second successive gold in the discipline after a triumphant race against the clock in Beijing in 2008.
Armstrong was last of the 24 riders to roll down the start ramp and led at every time check, with world champion Judith Arndt of Germany second in 37:50.29 and Russia's Olga Zabelinskaya, who finished third in Sunday's road race, taking bronze in 37:57.35.
In the Aquatics Centre, Daniel Gyurta of Hungary set a new world record in winning the men's 200m Breaststroke.
Gyurta lowered Christian Sprenger's world mark by 0.03 seconds to 2:07.28. Britain's Michael Jamieson was second with Japan's Ryo Tateishi third.
China's Liuyang Jiao won the women's 200m Butterfly and Nathan Adrian edged out James Magnussen by one-hundredth of a second in the 100m Freestyle.
Great Britain celebrated their first gold medal of the London 2012 Games - which was swiftly followed by number two courtesy of Wiggins - after Helen Glover and Heather Stanning stormed to victory in the final of the women's Rowing Pair.
Glover and Stanning dominated the field, winning by more than a length to make history at Eton Dorney as the first British female rowers to be crowned Olympic champions.
Australia pipped world champions New Zealand to win silver but neither crew was able to keep up with the blistering pace set by the British pair.
Ukraine cruised to victory in the women's Quadruple Sculls and Germany held off the challenges of Canada and Great Britain to take gold in the men's Eight.
South Korean teenager Jangmi Kim beat reigning Olympic champion Ying Chen of China with her final round to win gold in the women's 25m Pistol while world champions Kai Qin and Yutong Luo maintained China's dominance in the Diving with gold in the Synchronised 3m Springboard.
Italy's Daniele Molmenti celebrated his 28th birthday with gold in the men's Kayak Single (K1).
The current European champion, who could only manage 10th in Beijing, won in a time of 93.43, ahead of the Czech Republic's Vavrinec Hradilek in silver and Germany's Hannes Aigner, who claimed bronze.
In the men's Hockey, Australia defeated Spain 5-0, Pakistan beat Argentina 2-0, New Zealand stunned India 3-1 and Holland overcame neighbours Belgium 3-1 while South Africa drew 2-2 with Great Britain.
On the Basketball court, France's women's team saw off Canada 64-60 to secure their place in the quarter-finals, as did China following their 76-52 thrashing of Angola.
Australia edged Brazil 67-61, while Russia beat Great Britain by the same score. The Czech Republic overcame Croatia 89-70.
Brazil's men's footballers continued their impressive progress with a 3-0 defeat of New Zealand and Egypt joined them in qualifying for the last eight from Group C with a 3-1 defeat of Belarus.
Great Britain, Senegal, Mexico, the Republic of Korea, Japan and Honduras also advanced to the last eight.
World champion Lucie Decosse claimed Olympic Judo gold for France with victory over German Kerstin Thiele in the women's Middleweight (63-70kg) final at ExCeL while Dae-Nam Song triumphed in the men's Middleweight (81-90kg).
Xiaoxia Li caused an upset against Chinese compatriot Ning Ding to claim Olympic gold in the women's Table Tennis Singles.
Japan's Kohei Uchimura won Individual All-Around Artistic Gymnastics gold at the North Greenwich Arena.
Uchimura, who won silver in the competition four years ago in Beijing, scored 92.690 to see off the challenge of German Marcel Nguyen in silver medal position with American Danell Leyva in bronze, just under two points off the lead.
China's Xiaojun Lu won gold - and set a new world record - in the men's 77kg Weightlifting while Venezuela claimed just its second Olympic gold as Ruben Limardo won the Fencing Individual Epee.