* Ed Boone: Christopher’s father, who is a heating engineer. Up to the beginning of the story, he has been living with Christopher as a single parent for two years. He is usually very patient and understanding with Christopher, but gradually becomes cross with his son’s investigation.
* Judy Boone: Christopher’s mother. Christopher is told by his father that she died of a heart attack before the start of the book. Not much of an initial description is given, but Christopher describes more about her as the story proceeds.
* Siobhan: Christopher’s teacher, friend, and mentor. She teaches him how society works and how to behave within its complex guidelines.
* Roger Shears (Mr Shears): he lived near the Boones but has left his wife before the story begins.
* Eileen Shears (Mrs Shears): one of the neighbours, who attempts to console Ed for a time after Christopher learns of his mother’s death.
* Mrs. Alexander: one of Christopher’s neighbours, who tries to help him, she is an older, kind women.
* Wellington: Mrs Shears’ large black poodle, which Christopher finds dead in her front yard. (roamed around the neighborhood)
* Reverend Peters: the reverend of Christopher’s school. He also invigilates Christopher’s examination.
* Toby: Christopher’s pet rat.