Napoleon Dynamite (JON HEDER) is a classic high school nerd. With wild hair, perpetually half-closed eyes and a tendency to breathe only through his mouth, he lives in his own nerdy world. In reality, he resides with his Grandma (SANDY MARTIN) and unemployed, thirty-something brother Kip (AARON RUELL) who's also a homebody nerd.
At school, he's befriended Pedro (EFREN RAMIREZ), a Mexican nerd who's looking for a date for the high school dance. When snobby Summer (HAYLIE DUFF) turns him down, he gets portrait studio worker Deb (TINA MAJORINO) to go with him.
When Napoleon's grandma ends up in the hospital following an ATV accident, his uncle Rico (JON GRIES) shows up. A nerd stuck in a former era, he enlists Kip to help him sell Tupperware-like products. As Napoleon deals with them and the other daily trials and tribulations of his unique life, he also tries to help Pedro compete against Summer for the position of class president.