"I won't ever do it again," the fashion maven and mom, formerly known as Posh Spice, said. "Doing the Olympics was an incredible honor. I was so proud to do it; proud to be British..."
"That was a perfect time to say, 'That's great. Thank you to everybody, but no more.' Sometimes you've got to know when it's time to leave the party," Beckham told Vanity Fair for the magazine's Italy and Spain editions.
But even if Beckham has put the days as a Spice Girl firmly behind her, she says the spirit of the pop group lives on in her work as a designer.
"The Spice Girls were successful because we celebrated women," she said. "That's why I do what I do today."
Beckham's cover hits newsstands in Spain on Tuesday and Wednesday in Italy.