* Stanley Yelnats IV: The protagonist, an unlucky boy who is sent to Camp Green Lake for a crime he didn't commit. He's kind and resourceful, and his digging skills eventually lead him to uncover a secret about his family history.
* Zero (Hector Zeroni): A troubled and misunderstood boy at Camp Green Lake who becomes Stanley's friend and companion. He's strong and has a deep connection to the land.
* Kissin' Kate Barlow: A legendary outlaw and former schoolteacher who was unjustly accused of stealing. She's brave, independent, and compassionate.
* Sam: Kate Barlow's lover, a farmer who is forced to leave the area due to prejudice.
* Mr. Sir (Mr. Pendanski): The cruel and sadistic warden of Camp Green Lake, who is determined to force the boys to dig holes for no apparent reason. He's a complex and manipulative character.
* X-Ray: The tough and cynical leader of the group of boys at Camp Green Lake. He's initially skeptical of Stanley but later becomes his friend.
* Squid: A timid and sensitive boy who is often bullied by X-Ray. He's loyal to his friends and becomes more confident as the story progresses.
* Zigzag: A mischievous and playful boy who is always looking for a way to get out of trouble.
* Armpit: A large and strong boy who is often used for his physical strength. He's kind-hearted but easily influenced by others.
* The Warden's Mother: A mysterious and manipulative woman who plays a key role in the events of the story.
* The Mayor: The corrupt and greedy mayor of Green Lake, who is responsible for the town's decline.
* The Warden's Brother: A lawyer who is hired by the Warden to help her cover up her crimes.
These are just some of the main characters in "Holes." There are many other interesting and complex characters that contribute to the rich tapestry of the story.