Cast and CrewEdit

Character name Portrayed by Brief biography
Tom Baker Steve Martin The father of the twelve children and husband of Kate Baker. Tom grew up in a large family and wished that his own family would be the same. He was a college footballer, beginning his relationship with Kate in his school years, and developed ambitions to become a professional football coach. He and Kate had several offspring together and reside with their children in the countryside.
Kate Baker Bonnie Hunt The mother of the twelve children and wife of Tom Baker. In her childhood, she lost her sister and grew up in a small family. Wishing she had a bigger family like what her children have now, she had dreams of becoming a journalist in Illinois and writing for the newspaper; however, she moved to the countryside with Tom in the early 1990s and began her new life there with him and their children. Baker appears to have a talent in writing and has had one of her books published. She is known to be 44 years old.
Nora Baker Piper Perabo The oldest child of the Bakers, 22-year old Nora has some difficulties balancing her large family and her own adult life. She is dating an aspiring actor named Hank, who expresses his dislike for Nora's numerous siblings. Tom doesn't approve of Hank's habit of "sleeping over" at their house. Nora is called upon to be the babysitter when Kate leaves on her book tour, as the other kids look up to her and usually listen to her.
Charlie Baker Tom Welling 17-year old Charlie is a football player he had got kicked off the football team when they moved to the new town due to the fact that he found that it was not his dream, but that it was his father's. Charlie Baker had a girlfriend named Beth when the Bakers lived in Midland. Their relationship became distant upon moving away, but he still keeps regular contact with her. Charlie notes that the move has "ruined his life" and becomes angry with his father and their current situation.
Lorraine Baker Hilary Duff 15-year old Lorraine is the fashion queen of the Baker family and is anxious about getting out of big sister Nora's hand-me-downs. Because of this, she and sister Sarah often bump heads. When Kate and Nora are gone, she feels uncomfortable about being the woman of the house.
Henry Baker Kevin Schmidt Henry Baker is a player of the clarinet, and he has a good relationship with his older brother, Charlie, but not any of the other children. After the move, Charlie's anger about the situation begins to push them apart. He is often seen picking on Mark, Kim & Jessica, who are some of the other small children.
Jake Baker Jacob Smith Jake is one of the younger children of the house; he rides a skateboard and regularly refers to people as dudes. He's not exactly the smartest kid. He has a very forward personality and is protective of the younger siblings. Jake gets into a fight with two bullies at his school after he learns that they have been picking on Mark.
Sarah Baker Alyson Stoner Sarah is described as the tomboy of the house, which is exemplified in her always causing trouble. Because of this, she often gets in trouble and she quarrels with Lorraine. She has been known to play lacrosse and is said to have a dark gift, as her father Tom has quoted, being behind several schemes to get rid of Hank, sister Nora's kid-hating boyfriend.
Mark Baker Forrest Landis Due to his red hair and freckles, his siblings call him FedEx, meaning that because he looks so different from the other children, he must have been delivered to the wrong family. He likes animals, mostly frogs and snakes. He owns a frog named Beans which often gets himself into trouble. He is frequently picked on at school. He also likes Trains, as most little boys do. This is shown when Tom finds him on a Train en route from Chicago to Midland.
Kim and Jessica Baker Morgan York (Kim)
Liliana Mumy (Jessica)
Kim and Jessica are fraternal twins, but usually speak in unison. They appear to be highly observant and often correct people, including the teachers. Kim is the first to notice that Mark is being picked on by the bullies at school.
Mike Baker Blake Woodruff Mike Baker, is the tenth child and second youngest in the Baker Family, who is roughly around six years old and is in the First Grade at Evanston Elementary School. He shows a particular interest for karate and hockey. This is shown during the film in a few scenes where he is dressed in his white karate and hockey costumes. He also wears a white athletic cup which Sarah discovers in the Dish Washer. He is especially close to his older brother Jake. He is a very huggy person in this film.
Kyle and Nigel Baker Shane Kinsman (Kyle)
Brent Kinsman (Nigel)
Kyle and Nigel are the youngest children of the house and are identical twins. They appear to be very energetic and sometimes nasty, such as throwing toys at their preschool teacher. They also enjoy dressing in a variety of different costumes and outfits.
Hank Ashton Kutcher Uncredited Hank is Nora's boyfriend and is aspiring to be an actor. He dislikes children, especially Nora's younger siblings, as shown when he is more caring towards his freshly painted car than Nora's siblings.
Shake McGuire Richard Jenkins Tom Baker's superior. Described by Kate as a "hot dog" and by Kyle and Nigel a "wiener". He is the head of the athletic department at Illinois PolyTech University.