The sports star, who captained England and played for clubs including Manchester United and Real Madrid, will return to the east London pitches where he played as a child.
His mission is to help a struggling side survive in their amateur league.
Disney says the team and their community will go on "an uplifting, transformative journey of a lifetime".
Beckham said: "It is fantastic to be making Save Our Squad and to shine a light on the kind of grassroots football that I experienced growing up and which gave me so much at the start of my life in the game.