Big Fat Liar is a 2002 American comedy film, directed by Shawn Levy and starring Frankie Muniz, Paul Giamatti, and Amanda Bynes.
Jason Shephard (Frankie Muniz), a fourteen-year-old boy residing in the fictional town of Greenbury, Michigan, is known as a stealthy but not-well-organized liar by his friends and family. His English teacher, Ms. Phyllis Caldwell (Sandra Oh), assigns her class a creative writing essay; having not done it, Jason lies by telling a tale that his father had choked on a Swedish meatball, with the result that Jason was in the hospital's ER during night and therefore unable to complete the assignment. Ms. Caldwell claims that this is a lie. When asked for his father's office telephone number, Jason gives the number of his own cell phone instead. Jason has classmate and best friend Kaylee (Amanda Bynes) act as Jason's father's receptionist, while he, in a raspy voice, re-enacts the Swedish meatball tale. Ms. Caldwell apologizes and tells Jason to take his time with the assignment. The lie, however, is made ineffective when his parents are called into school to confront Jason's fib. It is revealed that if Jason cannot complete the assignment, he must study the course again in summer school; however, Ms. Caldwell tells Jason that if he can submit a handwritten essay at the community college by 6:00, she will consider counting it as a valid contribution – if it is original.
Jason, therefore, writes a story entitled "Big Fat Liar". Having been robbed of his skateboard by a bully, he borrows his sister's bicycle and rides it to the college. En route, he is teased by others for riding a girl's bike; distracted, he has a collision with a limousine. After being confronted by the driver, he asks to be driven to the college. The arrogant Hollywood film producer Marty Wolf (Paul Giamatti), who had engaged the driver, denies Jason a ride until Jason suggests that his neck is stiff, making himself eligible to sue for whiplash. Marty therefore allows Jason to enter the limousine. While riding, Jason expresses his dislike for the movies Wolf has produced as well as their common ability to successfully deceive. When the limo reaches the college, Marty Wolf advises him "The truth is overrated". Jason exits the limo, thanking the men for the ride.