Christopher John Francis Boone
At the start of the novel, Christopher is 15 years, 3 months and 2 days old. Christopher has Asperger's syndrome and is the narrator of this novel. He has the difficult relationship with other people common to those with severe Asperger's, and he doesn't like to be touched. He is incapable of telling lies. When he finds out about Wellington's death, he decides to begin a search for his killer. He is ambitious and wants to be a scientist. He is interested in the stars and science and the universe and by the end of the novel manages to take his A-level in maths.
Wellington
Mrs Shears' poodle. Wellington is found dead by Christopher at the very beginning of the novel, with a garden fork sticking out of him. The discovery prompts Christopher to begin 'detecting' to find out who killed him. This is the catalyst for the whole novel.
Ed Boone
Christopher's father. He works in the boiler business. He is the sole caregiver of Christopher, and has been since Christopher's mother died, two years before the start of the novel. Christopher's father looks after Christopher, knows all his habits, and understands the way Christopher works, but when he finds out that his son is trying to solve who killed Mrs. Shears' dog he becomes unusually angry and impatient. We learn that he killed the dog and that he lied about Christopher's mother being dead, and this prompts Christopher to leave home and make his first journey alone.
Siobhan
Christopher's friend of eight years and a member of the staff at his school, where he studies with other children with learning difficulties. To help Christopher understand human emotion, she draws faces for him so that he can identify that a smile means happy, a frown means angry and so on. It is Siobhan who sets the assignment that propels Christopher to write his novel, and she gives him writing tips throughout. She is very patient with Christopher and encourages his writing.
Mrs. Eileen Shears
Owner of Wellington, the poodle. A neighbor and friend of Ed's, she lives on the opposite side of the road, two houses to the left. She screams and screams when she sees Christopher with her dead dog. When she sees the dog spouting blood from the holes that have pierced it with the fork she doesn't pick it up. Christopher thinks this might be because she doesn't want to get dirty. These clues might lead to understanding her character but because Christopher doesn't deal with 'character' in a standard way, it is difficult to tell. We learn later in the novel that Mrs Shears' husband ran off with Christopher's mother, Judy. Later, Mrs. Shears had a relationship with Ed Boone. The relationship turned sour, which is what prompted Ed to attack the dog.
Mrs. Alexander
Another (older) lady who lives on Christopher's street, at number 39. Mrs. Alexander offers Christopher squash and biscuits when he visits her. Even when his father forbids him from interviewing the neighbors about Wellington, Christopher speaks to her. He asks her if Mr. Shears may have wanted to upset Mrs. Shears, and she reveals that Mr. Shears and Christopher's mother had an affair before she died.
Judy Boone
Christopher's mother. We are told very early on that Christopher's mother died two years ago - there was something wrong with her heart, and Christopher didn't visit her at the hospital. When Christopher discovers letters from his mother in his father's room, he realizes that his father was lying. He no longer trusts his father. He begins his journey to London to find his mother, who is living with Mr. Shears. She finds Christopher hard work, and when Christopher and Mr. Shears do not get along, she says she is only just managing to keep it together. At the end of the novel, Judy has moved back to Swindon and Christopher is living with her.
Toby
Christopher's pet rat. Christopher looks after him and feeds him and cares for him very well. Christopher rescues Toby from the tracks of the London Underground by jumping off the platform and searching for him, and manages to get out just before a train comes. Toby is the companion that Christopher takes with him on his journey to find his mother.
Mr. Roger Shears
Used to be married to Mrs. Shears until he ran off with Christopher's mother to London. He is the initial suspect in Christopher 'detecting'. When Christopher arrives at his house, having been searching for Judy, Roger is cruel to him and says 'You think you're so fucking clever, don't you? Don't you ever think about other people?' He totally misunderstands Christopher, and so Judy leaves him and moves back to Swindon with her son.
Uncle Terry
Christopher's uncle who lives in Sunderland and works in a bread factory.
Grandma Burton
Christopher's grandmother who lives in a home and has senile dementia.
Terry
A boy at school - older brother of Francis - tells Christopher that he will 'only ever get a job collecting supermarket trollies or cleaning out donkey shit at an animal sanctuary' and that 'they didn't let spazzers drive rockets that cost billions of pounds.' Having told us what Terry says, Christopher writes that he is going to go to University and study maths and/or physics.
Mrs. Peters
Teaches art at school and helps Christopher make a Get Well Soon card for his mother, when she is in hospital.
Mrs Gascoyne
Headmistress of Christopher's school. She doesn't want him to take A level Maths because she says the school doesn't have the facilities for students to sit A-levels, but when Ed shouts at her she concedes.
Reverend Peters
Mrs. Peters' husband, who comes into school to talk about God and heaven. He can't answer Christopher's questions about where heaven is or where God is.
Rhodri
A friend of Ed's who also works in maintenance and who occasionally joins Ed for a drink while they watch TV.
