Oh, and there's this thought...Will Nova and Cornelius merge or fall in love in the future? Anything could happen.
- Andy Serkis as Caesar, an intelligent common chimpanzee who is leader to a tribe of genetically enhanced apes.
- Steve Zahn as "Bad Ape", a common chimpanzee who lived in a zoo before the Simian Flu outbreak and was a hermit before joining Caesar's tribe.
- Karin Konoval as Maurice, a wise and benevolent Bornean orangutan who is Caesar's adviser.
- Terry Notary as Rocket, a common chimpanzee who is Caesar's brother-figure.
- Ty Olsson as Red, a Western lowland gorilla who was once a follower of Koba, now serving the Colonel to defeat Caesar. Olsson previously played Chief Hamill in Rise.
- Judy Greer as Cornelia, Caesar's wife.
- Max Lloyd-Jones as Blue Eyes, Caesar and Cornelia's oldest son.
- Devyn Dalton as Cornelius, Caesar and Cornelia's youngest son and Blue Eyes' younger brother. Dalton previously played Cornelia in Rise.
- Sara Canning as Lake, a common chimpanzee in Caesar's tribe. (Beloved of Caesar's eldest son)
- Michael Adamthwaite as Luca, a Western lowland gorilla in Caesar's tribe.
- Aleks Paunovic as Winter, an albino Western lowland gorilla in Caesar's tribe.
- Alessandro Juliani as Spear, a common chimpanzee in Caesar's tribe.
- Woody Harrelson as The Colonel, an iron-fisted soldier obsessed with wiping out Caesar and his tribe to preserve his people's role as the dominant species.
- Amiah Miller as Nova, a bold and kind war orphan whom Maurice adopts as his daughter.
- Gabriel Chavarria as Preacher, a human soldier.
- Chad Rook as Boyle