The Beatles singer closed the spectacular event, which kicked off the games in London last Friday, but was given only a token fee for his appearance.
Paul - who played tracks The End and Hey Jude on the night - said he didn't mind waiving his usual fee, particularly as he would receive tickets for the Games as a thank you from the Olympic committee.
He said: "They don't pay you to perform, but what does happen is you get tickets to events, so they asked me what I would ideally like to go to, and so I sent a little list.
"I'm a big fan of athletics, when that's on the TV, I don't go out, so the Olympic Games are great for that for me."
Many of the other acts who performed at the event - for which seats cost up to £2,012 - such as Dizzee Rascal, Arctic Monkeys, Frank Turner, Emeli Sande and Mike Oldfield, were also thought to have only been paid the nominal fee, required for contractual purposes.
Many of the actors, dancers and performers who appeared at the ceremony also volunteered their services for free.
Speaking after his performance of Bonkers at the event, Dizzee - who was brought up near to the Stratford stadium where the opening ceremony took place - said: "It is a good time for the UK and I am glad they asked me to perform one of my greatest tracks to represent the country.
"Huge respect to all the athletes who are taking part and let's get the party started."