In 1988, Dottie Hinson reflects on her past while attending the grand opening of the All-American Girls Professional Baseball League exhibit at the Baseball Hall of Fame. The sight of familiar faces and photographs sparks a vivid flashback to 1943.
As World War II looms over Major League Baseball (MLB), Chicago Cubs owner Walter Harvey convinces other team owners to fund a women's league, appointing Ira Lowenstein as its leader. Talent scout Ernie Capadino watches Dottie, who plays an impressive catcher for a local dairy in Oregon, but she is content awaiting her husband Bob's return from the war. However, her younger sister, Kit Keller, eager to prove herself, persuades Dottie to pursue the opportunity after Capadino brushes her aside.
The sisters journey to Harvey Field in Chicago for tryouts. On their way, they convince Capadino to accept the talented but unconventional second baseman Marla Hooch. The tryouts lead them to an eclectic group of women, including Mae "All-the-Way-Mae" Mordabito, bouncer Doris Murphy, and several others, eventually forming the Rockford Peaches, alongside competitors like the Racine Belles and Kenosha Comets.
Led by the hard-drinking, jaded former star player Jimmy Dugan, the Peaches struggle under his aloof demeanor, forcing Dottie to step up as the team leader. One pivotal moment occurs when Dottie makes a stunning play that graces the cover of Life magazine, increasing the league's visibility and drawing in crowds, though the owners remain skeptical.
As the Peaches build camaraderie, the team members face personal hurdles - Marla gets married, Mae helps Shirley learn to read, and Evelyn pens a song for the team. Dottie finds herself at the center of attention, leading to a growing tension with Kit, ultimately leading to a trade that sees Kit join the Belles.
As the season concludes, the Peaches boast the best record, qualifying for the World Series. Tragedy strikes when Betty learns of her husband's death in combat, prompting her departure from the team. The evening takes a surprising turn when Bob, injured but discharged, reunites with Dottie. Despite Jimmy's urging, Dottie decides to leave with Bob, believing she'll regret missing the Series.
The final showdown of the World Series, culminating in a dramatic seventh game, pits Dottie against Kit, now the Belles' pitcher. Tension escalates as Dottie’s hit helps the Peaches take the lead, but Kit makes a triumphant play, scoring the winning run, even while knocking the ball from Dottie's grip.
The triumphant game leads to a pivotal moment of reconciliation between the sisters, alongside the realization of the owners' renewed faith in Lowenstein’s league vision.
Returning to the present, Dottie reconnects with her former teammates at Cooperstown, reflecting on how far they’ve come. In the bittersweet reunion, they gather for a photo and reminisce about the past while playing baseball once more, evoking the spirit of the game they loved.
