Wiggins wins time trial to become Britain's top Olympian
Wiggins overhauled legendary rower Steve Redgrave's total of six medals as he beat stiff competition from German world champion Tony Martin to seal victory in 50 minutes, 39.54 seconds.
The winning margin over Martin was 44 seconds.
Britain's Chris Froome grabbed the bronze, clocking 51 minutes 47 seconds.
Defending Olympic champion Fabian Cancellara of Switzerland was unable to challenge for the podium, finishing fourth.
Wiggins had done most of the damage by the 29 km mark, when he had a 22-second advantage over Martin.
It is turning into a dream summer for the 32-year-old Wiggins, who last month became the first Briton to win the Tour de France yellow jersey.
It is his fourth career Olympic gold, after taking the individual pursuit title in 2004 and 2008, and the team pursuit in Beijing.
The other medals are one silver, in the 2004 team pursuit, and two bronze, in the 2004 madison and 2000 team pursuit.