The 73-year-old rocker thinks the British group made the "biggest mistake" of their career by saying they'd give the legendry Fab Four a run for their money during a controversial interview with MTV in 1996.
Speaking to Q magazine, Sir Paul said: "'Oasis were young, fresh and writing good tunes. I thought the biggest mistake they made was when they said 'We're going to be bigger than The Beatles''.
"I thought, 'So many people have said that, and it's the kiss of death.'
"Be bigger than The Beatles, but don't say it. The minute you say it, everything you do from then on is going to be looked at in the light of that statement."
Noel Gallagher - who was joined by brother Liam Gallagher in the pioneering Britpop band, which broke up in August 2009 - was roundly criticised when he made the claim.
He has since stated that he had no recollection of saying it, and was probably on drugs.
He previously admitted: "I might have been high when I said that. I think I was."
Sir Paul's comments come after he admitted he was gripped by depression, drank and and almost walked away from his music career when the band - which also included John Lennon, George Harrison, and Ringo Starr - went their separate ways in 1970.
"I was depressed at the time, yeah. You would be too. I was breaking from my lifelong friends, not knowing whether I was going to continue in music," he said.
"I took to the bevvies. I took to a wee dram. It was great at first, then suddenly I wasn't having a good time.
"It wasn't working. I wanted to get back to square one, so I ended up forming Wings."
