Joe Dirt is a
janitor at 98.6 KXLA, a
Los Angeles-based radio station, and is brought before a
shock jock named Zander Kelly who speaks of his life story while on the air. Joe reveals that as a baby he had a
mullet wig installed
because the top of his skull had never formed. At age 8, he was left behind by his parents and sister at the
Grand Canyon and thus does not know his real
surname. After growing up in a series of
foster homes, Joe ran away until he arrived in Silvertown, a small chicken town in
Idaho. There, he met Brandy and her dog, Charlie, and became a target of jealousy from Robby, the town bully, who also vied for Brandy's affection. After Brandy's alcoholic father shoots Charlie dead after a hunting accident that cost him his leg, Joe decides to try to find his parents. He details his adventures across the country including discovering what he believed to be a
meteorite, only to discover it was solid excrement buildup that fell from a
commercial airplane. He invertedly took a hot air balloon to
North Dakota where he took a job at an
oil well while making enemies with a
wildcatter. He even made friends with Kickin' Wing, an unsuccessful
Native American fireworks salesman in
New Mexico while acquiring a list of names for those on the 1979 Grand Canyon tour. Afterward, he met a woman named Jill while working on the fair ground and while dating her, he learned about her time being separated from her parents, assuming it was his sister. In
Indiana, Joe has an encounter with a
serial killer named
Buffalo Bob, who is parodying the lotion scene from
The Silence of the Lambs. After Buffalo Bob is arrested, this event brought Joe unwanted attention from the media but helps his search. Joe discovered his roots started in
Louisiana where he went to next. There he took a job as a high school janitor working with Clem Doore, a former mobster in the
Witness Protection Program. Clem rescues students after a
mustard gas explosion and informs the media Joe was the hero. Joe then revealed Clem to be the hero, unaware that the Mafia wanted his head. Clem managed to survived the encounter and tipped Joe on the vehicle that his parents used, the Rambler Wagon, to be extremely rare. While traveling on further he came across an
alligator farm and met the owner, Charlene. Looking to make money, he was hired to be an alligator wrangler for audiences. After one encounter with an alligator in which he landed wrong, he had an epiphany about his little sister yelling at Joe about why his last name was Dirt and not his real surname Nunamaker. Upon realizing his real last name, Joe discovers the address of his old family home and he travels to
Baton Rouge, only to find that they moved away many years prior. Listening to Joe's story, both Zander and the radio audience initially find him an object of scorn, but Joe's kindness and optimistic outlook on life win them over. Eventually, Joe lands the janitorial job at the radio station, where he recounts how he gave up the search and returned to Silvertown to be with Brandy. However, Robby informed him that he and Brandy were getting married and that she found Joe's parents but instructed him not to tell Joe. Zander calls Brandy to find out why, and she tells Joe his parents were killed the day they were at the Grand Canyon; she pleads with Joe to return to Silvertown. Upset by the news, Joe stays in Los Angeles. Joe is unaware that he has become a media sensation, but he quickly discovers his newfound fame. An appearance on
TRL results in a phone call from a woman claiming to be Joe's mother. Joe meets his parents living in
Simi Valley,
California, and he discovers that they intentionally abandoned him and that they only reconnected with him to boost their sales of clown figurines. Joe storms out, officially cutting ties with his parents. He intends to commit
suicide, but Brandy arrives and finally admits that she lied to him about his parents being dead because she had to protect him from them and their greed after she found out what horrible people they were. Brandy revealed that Robbie lied about the engagement, expressing her love and convinces Joe to come home with her, but he suffers a head injury after a police officer
lassos and accidentally causes him to fall off a bridge hitting his head while springing back up. Joe wakes up in Brandy's house, surrounded by his friends: Kickin' Wing, who reveals that thanks to Joe he now owns 30 successful firework stands, Clem (who is now under the name of
Gert B. Frobe) and Charlene (who sold the alligator farm after losing her thumb and middle finger except her ring finger on her left hand to one of the alligators), who are now engaged. Brandy reveals that she got Joe a
dreadlock wig following his head operation, has retrieved his
Hemi, and she has a new dog that Charlie fathered. As they prepare to take a ride in Joe's Hemi, Robby arrives and tells Joe that no one wants him in Silvertown. Clem threatens Robby and exclaims that they are Joe's family. Robby challenges Joe to a race and Joe leaves him in the dust as Robby's car malfunctions and breaks down. As they drive away, Zander dedicates
a song to Joe on the radio. ==Cast==