Weir underlined his status as the world’s best wheelchair athlete by winning the men’s T54 marathon with a sprint finish on the Mall.
It completed a clean sweep for the 33-year-old from south London, who had already won gold in the 5,000m, 1500m and 800m, and took Great Britain’s final medal count to 120 – surpassing their target by 17.
“I had to be in superhuman state to win four and I’ve done it,” said Weir, who won two gold in Beijing four years ago and may now retire.
“This last 10 days have been incredible. I’ve never experienced anything like it in my life, it just shows the British public are so supportive, they just enjoy watching us and are so proud to put these Games on.”
Fellow Briton Shelly Woods made up for her three defeats on the track with a silver medal in the women’s T54 marathon.
“It has been such a tough week and I’ve been wanting a medal so badly,” Woods said. “This means the world to me. I was hoping I could do it on the track, but a silver in the marathon is amazing.”
Weir’s fourth gold at London 2012 saw him match the haul of British cyclist Sarah Storey, who also won all of her events, both in the Olympic Velodrome and on the road. Great Britain ended the Games in third place in the medal table.