Emma Stone was initially cast as Billie Jean King, but scheduling issues forced her to pass on the role. Brie Larson was ultimately tapped to replace Stone. After a few months, Larson dropped out. After Stone's schedule was cleared, she was able to take back the role.

In 1973, Billie Jean King was 29 and Bobby Riggs was 55. At the time of filming, Emma Stone was 28 and Steve Carell was 54.

Emma Stone has admitted that she is not very skilled at tennis.

Emma Stone put on 15 pounds of muscle for this film.

Jonathan Dayton and Valerie Faris previously directed Steve Carell in Little Miss Sunshine (2006).

Emma Stone performed on Broadway with Alan Cumming in Cabaret.

This is the second time Emma Stone and Steve Carrell have worked together since Crazy, Stupid, Love. (2011).

This is the first time Danny Boyle has produced but not directed a film since 28 Weeks Later (2007). Boyle was originally set to direct, but had to leave due to scheduling conflicts with Steve Jobs (2015) and T2 Trainspotting (2017).

Five of the supporting cast members are sketch comedy veterans. Steve Carell was a writer and cast member of The Dana Carvey Show (1996), Sarah Silverman was a cast member of Mr. Show with Bob and David (1995), Fred Armisen was a cast member of Saturday Night Live (1975) and a cast member/writer/producer of Portlandia (2011), Tom Kenny was a cast member of Mr. Show with Bob and David (1995), and Chris Parnell was a cast member of Saturday Night Live (1975).

This is the first time Emma Stone and Martha MacIsaac have worked together since Superbad (2007).

This will be the first time Emma Stone and Andrea Riseborough have worked together since Birdman or (The Unexpected Virtue of Ignorance) (2014).

Reunites Elisabeth Shue with Wallace Langham after CSI: Crime Scene Investigation (2000). However, they don't share any scenes.