The main protagonist of the film, Napoleon is a 16-year resident of Preston, Idaho, who fails to fit in with the rest of the sleepy town.
- Adorkable: A dorky highschooler with no social skills or talents, who nonetheless gets flashes of awesomeness.
- Ambiguous Disorder: He shows very little emotion, has no social skills, unusual interests and habits, and overall, looks and acts very awkward.
- Awesome Mc Coolname: Napoleon Dynamite.
- Blatant Lies: Lies frequently about his skills and things he's supposedly done, like hunting wolverines.
- Butt-Monkey: Suffers quite a bit of misfortune in the film, getting picked on by bullies, suffering Groin Attacks from Pedro's bike and Rico's time machine, and getting rumors spread about him by Rico.
- Catchphrase: Gosh! and (Friggin')Idiot!.
- Cloud Cuckoo Lander: Has many strange beliefs and does many strange things.
- Dull Surprise: Has only one facial expression throughout the entire film.
- '80s Hair: Sports a hideous perm.
- Girlfriend in Canada: His girlfriend couldn't make it to the dance because she's modeling in Oklahoma.
- Hollywood Nerd: Meets all the requirements. Glasses, no social skills, poor fashion sense, dorky hairstyle, and a mouth breather. Subverted in that he's not especially intelligent, and doesn't have any typical "nerd" interests.
- Jerk with a Heart of Gold: He's not a very pleasant person, but he genuinely befriends Deb and Pedro, and goes out of his way to help the latter become class president.
- Kavorka Man: In the animated series Deb pines after him. He also manages to woo Kip's girlfriend and dates a Japanese exchange student.
- Lovable Nerd: Despite his strange behavior and habits, he still manages to endear everyone with his willingness to help his fellow outcasts.
- Meaningful Name: His name is Napoleon and (height aside) he has all the hallmarks of The Napoleon Complex such as belligerence, a disproportionate ego and a desperate urge to prove himself.
- No Social Skills: Can't seem to hold a civil conversation with anyone.
- Sanity Ball: Despite being a Cloudcuckoolander, he shares this with Pedro, being more rational than other characters.
- Simpleton Voice: His really deep, monotonous voice.
- Terrible Artist: Draws a number of hideous pictures, though the ones of Trisha and the liger stand out.
- Trademark Favorite Food: Tater tots.
- Verbal Tic: Frequently sighs/exhales loudly, being a mouthbreather and all.
Deborah "Deb" Bradshaw
A fellow highschooler, Deb is attempting to earn money for college by selling handicrafts and taking professional photos, which causes her to cross paths with Napoleon. She soon becomes friends with him and Pedro.
- Adaptation Personality Change: In the movie Deb's interest in Napoleon didn't seem to extend beyond friendship. In the animated series she's clearly crushing on him. Deb is also slightly more extroverted.
- Ambiguous Disorder: Like Napoleon, she speaks in a monotone, has no social skills, and shows little emotion. She acts more normal when she's happy.
- '80s Hair: All her hairstyles, but particularly her side ponytail.
- Emotionless Girl: Shows very little, if any, emotion.
- No Social Skills: Clearly sounds uncomfortable when first talking to Napoleon.
- She Cleans Up Nicely: Subverted during the dance, where she still looks dorky despite the change in dress and hairstyle. Played straight at the end, where she looks nicer after switching to a more conventional hairstyle.
- The Not-Love Interest: To Napoleon, and to a lesser extent, Pedro. Their relationships never go beyond just being friends.
- Tomboyish Ponytail: Sports a side ponytail for most of the film.
- When She Smiles: Finally smiles at the end of the film, and it is quite pretty.
Pedro is the first friend we see Napoleon make in the film. A transfer student from Mexico, he struggles to fit in.
- Composite Character: Of Giel and Pedro from Peluca, Jared Hess's original short that inspired the main film.
- Dogged Nice Guy: To Summer, who turns down his request to go to the dance with him.
- Dull Surprise: He shows no emotion at all, until he wins the class presidency.
- Foreign Exchange Student: A transfer student from Mexico.
- Gag Haircut: Ends up shaving his head after his head gets "hot", forcing him to get a wig from Deb.
- Magnificent Moustaches of Mexico: Napoleon thinks so.
- Nice Guy: One of the nicest compared to the other characters.
- Only Sane Man: The most normal of all the characters.
- Sanity Ball: Shares this with Napoleon.
- South of the Border: Hails from Juarez, Mexico.
- When He Smiles: Finally smiles at the end, when he becomes class president.
Kipland "Kip" Dynamite
Kip is Napoleon's unemployed 32-year old brother, who spends all his time on the Internet talking to girls in chatrooms.
- Aloof Big Brother: Tries to be this, but whatever advantage he has over Napoleon is pretty lame.
- Catchphrase: Jeeze!
- Hollywood Nerd: In the same vein as Napoleon.
- Hollywood Tone-Deaf: Just listen to the song he sings in the after-credits scene.
- Jerkass: Not to the same extent as Uncle Rico, but his know-it-all attitude towards Napoleon and that one snide jab he made about Deb's mother shows that he's kind of a dick.
- Manchild: Still lives with his grandmother at age 32.
- Porn Stache: Combined with his oversized glasses and receding hairline, it makes him look more like Napoleon's dad than his brother.
- Pretty Fly for a White Guy: He gets a gangsta makeover from LaFawnduh.
- Sickening Sweethearts: With LaFawnduh.
- Simpleton Voice: His voice is a bit high-pitched for someone of his age.
- Ugly Guy, Hot Wife: Marries the stylish, curvy LaFawnduh.
- What the Fu Are You Doing?: Claims to be training to be a cage fighter, but if his "fights" with Rex and Napoleon are any indication, he hasn't got it.
Napoleon and Kip's uncle Rico is a former high school football player, who lives in a trailer van. His goal in life is to return to 1982, so he could take part in the big game he was forced to sit out and go professional. He is asked to look over Napoleon and Kip after their grandmother breaks her coccyx.
- Adaptation Personality Change: Went from being an overconfident Jerk Jock in the film to being superstitious and occasionally submissive in the animated series.
- Cool Car: A 1975 Dodge Tradesman.
- I Coulda Been a Contender!: Parodied. He wants to go back in time to 1982 in order to play in the big game and become professional. As it turns out, he was a bench warmer.
- Dirty Old Man: He tries to sell bust enhancers to Deb, Napoleon's classmates, and Rex's wife. The latter gets him beat up.
- Jaded Washout: After failing the big game in 1982, he hasn't done anything with his life since.
- Jerkass: Is rude and dismissive to Napoleon.
- Jerk Jock: Throws his weight around, due to being more masculine than his two nephews. One stand-out moment being when he took Kip's steak and lobbed it at Napoleon.
- Malicious Slander: Spreads false rumors about Napoleon to his classmates.
- Put Me In, Coach!: Coach left him on the bench during the big game in 1982. Rico wants to go back for a second chance, thinking that winning the game will make him famous.
- Screams Like a Little Girl: When Napoleon pegs his van with a grapefruit while he's driving.
- '70s Hair: A greasy brown helmet. Also goes with his Porn Stache, denim vest and wide lapels.
- Snake Oil Salesman: Tries to sell herbal "bust enhancers".
- Trademark Favorite Food: He's frequently seen eating steak.
Carlinda "Grandma" Dynamite
Napoleon and Kip's grandmother.
- AcCENT upon the Wrong SylLABle: Pronounces "quesadilla" as "quesa-dilluh".
- Cool Old Lady: Goes quadbiking, despite her age, AND can beat many people a fraction of her age in the annual Preston Bed Race.
- Grumpy Old Lady: In the TV series.
- Named by the Adaptation: Her first name, Carlinda, is only given in the TV series.
Preston High School
Summer is a popular girl at Preston High School, and Don's girlfriend. She runs as class president against Pedro during the latter half of the film.
A fellow classmate of Napoleon's, and one of Summer's friends. Napoleon asks her to the dance.
Don is a jock classmate of Napoleon's, who occasionally antagonizes him.
Randy is a Preston High School student who frequently bullies Napoleon.
Svadean is the principal of Preston High School, seen occasionally throughout the film.
A tae kwon do instructor in Preston, Napoleon and Kip briefly visit him after seeing an ad for his self-defense program.
- Large Ham: As seen during his demonstration."BOW TO YOUR SENSEI!"
- Testosterone Poisoning: EVERYTHING about Rex is manly and tough. Even his wife!"The strength...of a GRIZZLY! The reflexes...of a PUMA! And the wisdom...of a MAN!"
- Wearing a Flag on Your Head: His American Flag pants and bandana.
- What the Fu Are You Doing?: His "demonstration" with Kip raises a few eyebrows at his reputation.
Kip's girlfriend from Detroit. They eventually marry.
- Alliterative Name: Her name before she marries.
- Chuck Cunningham Syndrome: She is completely absent from the TV series and nobody mentions her.
- Happily Married: To Kip in The Stinger.
- Sassy Black Woman: Subverted. While she looks the part, she's nothing but nice to Napoleon.
- Satellite Love Interest: We don't know much about her, except that she is madly in love with Kip.
- Small Role, Big Impact: She doesn't get much characterization, but she gives Napoleon the taped song that wins Pedro the class election.
- Ugly Guy, Hot Wife: Marries the gangly, awkward Kip.