Terms were not disclosed, but sources with knowledge of the deal say it's a five-year deal worth in the neighborhood of $5 million a year — the richest shoe deal for an NFL player and about two times more than any previous deal Nike had with a football player.
The deal will make Beckham a larger brand spokesman for Nike, including campaigns outside of football.
The deal got so big because Adidas wanted to take Beckham from Nike, sources said. Nike had the right to match the offer, which it did.
A Nike spokesman said the company wasn't commenting on the deal. The story was first reported by sneaker site NiceKicks.com.
"It was a long process," Beckham's agent, Zeke Sandhu, told ESPN. "This proved he's an icon."
Beckham's value not only comes from his flash on the field during games, but his ability to stay relevant off of it. He has 8.3 million Instagram followers, 2.3 million Twitter followers and 1.3 million Facebook followers.
He drew even more attention to himself and Nike with the shoes he wore before every game last year, customized by sneaker designer Troy Cole. One week, Beckham had Burberry Nikes; the next week, it was a "Back to the Future" tribute. Every design seemingly spread like wildfire on social media before games.
The deal was done by Sandhu and Beckham Jr.'s mother, Heather Van Norman, who is his business manager.