The film dramatizes the events that led to the 1973 match between Billie Jean King (Emma Stone) and Robert Larimore Riggs (Steve Carell) but also their personal life. King and Gladys Heldman (Sarah Silverman) face Jack Kramer (Bill Pullman), who announced the organization of a tennis tournament where the awards offered to women are an optimal one for men, despite the fact that ticket sales are equal for both categories.
King and Heldman threaten to start their own tournament if they are not treated equally, but Kramer refuses to change the terms by claiming and accusing that female tennis is inferior to masculine. Sometime later, he excludes the Lawn Tennis Association from the players who join the new tournament. The women’s tournament faces great difficulties until Heldman gets a sponsorship from a Virginia Slims cigarette company.
Meanwhile, outside the tennis court, Billie Jean begins an amorous adventure with Marilyn Barnett (Andrea Risenborough), her hairdresser, and jeopardizes her marriage to Larry King (Austin Stowell). On the other hand, Riggs’s marriage to rich Priscilla Wheelan (Elisabeth Shue) is also in an unfavorable position because of his addiction to gambling. Thrown in the street when he can not hide a car he has won on a bet, he has the idea of provoking the best female tennis player, being convinced and praising that at 55 nor can she beat any woman in this sport.