- Scarlett Johansson as Nicole Barber
- Adam Driver as Charlie Barber
- Laura Dern as Nora Fanshaw, Nicole's lawyer
- Alan Alda as Bert Spitz, Charlie's first lawyer
- Ray Liotta as Jay Marotta, Charlie's second lawyer
- Azhy Robertson as Henry Barber, Nicole and Charlie's son
- Julie Hagerty as Sandra, Nicole's mother
- Merritt Wever as Cassie, Nicole's sister
- Wallace Shawn as Frank
- Martha Kelly as Nancy Katz
- Mark O'Brien as Carter Mitchum
- Matthew Shear as Terry
- Brooke Bloom as Mary Ann
- Kyle Bornheimer as Ted
- Mickey Sumner as Beth
- Robert Smigel as Mediator
- Rich Fulcher as Judge Neil Tilden
- Lucas Neff as Pablo
- Tunde Adebimpe as Sam
Jasmine Cephas Jones, Mary Wiseman, Matthew Maher, Gideon Glick, Raymond J. Lee, and Becca Blackwell appear as members of Nicole and Charlie's theater group.
