American Vincent Hancock retained the title he won in Beijing with a score of 148 out of 150, ahead of Denmark's Anders Golding on 146.
Hancock shot all 25 clays in the final at an overcast royal artillery barracks in front of a capacity crowd on the outdoor range.
It was the second skeet gold of the London Games for the United States after Kim Rhodes took the women's title.
Meanwhile, Qatar's Nasser al Attiya took bronze behind Hancock and Golding in a shoot-out.
The Citroen World Rally Championship driver qualified for the final with the fourth-best score of 121 out of 125, and then hit 23 of his 25 targets in the final at the Royal Artillery Barracks to tie for third overall with Valeriy Shomin and force a shoot-out against the Russian.
Al-Attiyah, who won the Dakar Rally for Volkswagen in 2011, and has driven a semi-works Citroen DS3 WRC this season, hit all of his targets in the shoot-out to triumph 6-5 and secure his country's first medal of the 2012 games.