In the first film Charlie is 17 years old and a topical teenager that's hates everybody and just wants to be cool with a girlfriend named Beth. He has lived in Midland since he was 9 years old and plays the Quarterback position in his High School Football team, and, as such, he accuses his parents of ruining his life when they move to Evanston, IL. Frustrated and homesick, his relationship with his siblings suffers, who begin to view him as a "jerk." Charlie signs up for football at his new school, but is dismissed as a farm boy by the coaches, who refer to him as "skippy", mock him and his father about how Charlie's father sucked at football to Shake, and discriminate him for being a person from farmlands. He goes to his father to tell him about his concerns and how the school is being disrepectful to him, but finds that his father's preoccupation with his work has relegated his children to number two in his life.
Despite being a former quarterback, he is demoted to the position of defense upon signing on with his new team. He is regularly made sport of by the stars of the football team, who "moo" to imply his farm-background, refer to him as "Baker," mock his family's rural background, going so far as to stuff corn into his locker while he is showering after football practice, clearly humiliating him to a breaking point. He attempts to confront them physically, at the behest of his sister, but is convinced to avoid violence either because of school regulations or the advantage in numbers the bullies have. When finally deciding to not count on his parents to help him through it, instead, Charlie decides to start a new daily basis; he skips school and his grades suffer, and in return, he is kicked off the football team, much to his father's chagrin. Him being exiled from the football team causes his parents to finally notice how Charlie is suffering. His father tries to order him to stay with them and continue school but Charlie decides that he is done living there and wants to move back to Midland just as his mother comes back home from a business trip. When it is the evening he changes his mind and goes back home to discover that Mark has vanished as a result of him feeling unwanted by his siblings. His father for the first time in the move has a moment with Charlie, apologizing and telling Charlie that if he thinks that he only accepted the new job to gain popularity like his buddy Shake McGuire then he is correct. Charlie frantically goes to help the family in finding Mark, and when searching the city they discover that he is on a train bound to leave for Midland. However, the train drives off with Mark forcing the family to spend one night chasing it back to Midland where they reconcile. Later that Christmas Charlie has fully become part of the family and in the epilogue he is the first one to react to the new chandelier crashing to the floor.
In the second film Charlie is 19 years old and no longer with Beth. He works in an auto-shop to help pay for his tuition. When his family goes to Lake Winnetka Charlie, develops a relationship with Anne Murtaugh. He isn't really seen much in the film until the Labor Day Cup when his older sister Nora goes into labor. He is then seen carrying her into the hospital with her husband Bud. He is nephew of Tom McNulty.
Charlie Baker is portrayed by Tom Welling in both films.