Ender Wiggin
The protagonist. Ender is brilliant, empathetic, and terrified of his own capacity for violence. He's shaped by the adults around him into the perfect commander, but he never stops questioning what that shaping costs him. His arc runs from isolated child to accidental genocidaire to would-be redeemer.
Colonel Hyrum Graff
The head of Battle School and Ender's main handler. Graff genuinely believes in Ender and genuinely doesn't care what damage he does to get the result he needs. He's not a villain, but he's not a good person either. He makes the hard choices and lives with them.
Valentine Wiggin
Ender's older sister and the person he loves most. She's the empathetic pole that keeps him from becoming Peter. The teachers use her to pull Ender back when he shuts down, which she resents. She eventually chooses Ender over Earth, leaving with him to colonize new worlds.
Peter Wiggin
Ender's older brother. Peter is cruel, manipulative, and politically brilliant. He represents what Ender fears he could become. Ironically, Peter channels his aggression into politics and eventually unifies Earth's governments. He's a monster who does something good, which complicates the novel's moral picture.
Mazer Rackham
The hero of the Second Invasion, kept alive by relativistic space travel to train Ender. He's harsh and withholding during Command School training, continuing the pattern of deliberate pressure. He's the one who tells Ender the truth after the final battle.
Bean
The smallest and youngest student in Ender's Dragon Army, and the one who comes closest to understanding Ender's situation from the outside. Bean is nearly as gifted as Ender and becomes his most trusted subordinate. He sees through the teachers' manipulation earlier than anyone else.
Petra Arkanian
One of the few students at Battle School who befriends Ender early on. She teaches him the basics of the Battle Room and later serves as one of his key commanders at Command School. She's competent, loyal, and one of the few female soldiers Card gives real presence in the story.