The ex-Red is no stranger to lending his support to charitable causes and regularly makes appearances around the globe for the Manchester United Legends team.
The 39-year-old, who was a title winner during the 2002-03 season, was one of 50,000 runners taking part in the 26.2-mile race around the capital.
Speaking ahead of the race the South African midfielder explained what the race means to him and his motivation for taking on the challenge.
He said: “My London Marathon medal will probably mean more than my Premier League medal, because I’m doing it for Manchester United Foundation and it’s real-life stuff.
“When I started to be involved with the Foundation and I had the work they’re doing explained to me it was amazing.
“I found out that a third of the kids in Manchester grow up below the poverty line.
“That hit me so hard, because this is Europe, it’s Manchester, and you don’t really think about these things.
“It’s sad to say that you always relate that to places I come from, in South Africa, in the rest of Africa, but I never, ever thought it would be in Manchester. It’s just unthinkable.
“Of course, to play for Manchester United and have a Premier League medal, oh my goodness, it’s out of this world.
“But if I can raise a lot of money to help even one child then I will be so grateful, so happy, and it will be more than a medal for me.”
Quinton completed the race in the respectable time of 4:06:28 and was joined by a group of twenty Manchester United fans who had been selected to race on behalf of the Foundation.
You can lend your support and contribute to Quinton’s fundraising efforts by visiting: http://uk.virginmoneygiving.com/Quinton