|Media type||Print (Hardback and Paperback)|
|Preceded by||A Long Way Down|
|Followed by||Juliet, Naked|
- Sam Burns - A troubled 16-year-old skateboarder, Sam is scared and unprepared to be a father. His idol is Tony Hawk. He has a poster of him to whom he talks about skate tricks and his life. He has numerous dreams in which he is in the future, raising a child with Alicia.
- Annie Burns - Sam's 32-year-old mother. She has a hostile relationship with her ex-husband (Sam’s father). She struggles to raise Sam, and is devastated when she discovers his girlfriend, Alicia, is pregnant. She becomes involved with Mark, a man she once knew through work, and it is revealed later in the book that they have a child together.
- Dave Burns - An uneducated plumber, Sam’s father has no interest in raising his son.
- Rufus "Roofy" Jones - Sam and Alicia’s unplanned child.
- Alicia Jones - Sam’s girlfriend, who gets pregnant and refuses to have an abortion. She and Sam meet at her mother's birthday party, though they get off to an awkward start due to Sam's obvious flirting.
- Andrea Jones - Alicia's mother who is upset about the pregnancy. She is a Councillor in the Council organisation at which Annie is an employee.
- Robert Jones - Alicia's father who is upset about the pregnancy. He is a college professor.
- Mark - The new boyfriend of Annie. It is revealed in a "flash forward" that Mark and Annie will raise another child together.
- Rabbit - Sam’s skater friend who apparently has subhuman intelligence and reasoning skills, with excellent skating skills.
- Rubbish - Sam’s other skater friend who is apparently smart, with horrible skating skills.
- TH - Tony Hawk, his idol. Sam always talks to a poster of Tony that hangs in his room and Tony responds with a quote from his book. Tony's advice eventually stops making sense to Sam and discourages him.
- Alex - Sam’s girlfriend after he and Alicia split up.
- Carl - Alicia’s boyfriend after she and Sam split up.
- Emily - Annie's baby who is born after Rufus. She is the sister of Sam.
Southampton's Reading Slam
In Southampton, 800 copies of the book were freely distributed throughout the city. A message inside the specially printed books' front covers encouraged residents to "take me, read me, discuss me and then pass me on and then wait till it comes."
Slam is available on unabridged audiobook, read by Nicholas Hoult.