The characters of Dumb and Dumber, some of which appear in its sequel, Dumb and Dumber To.
Lloyd Christmas (Jim Carrey)
- Aesop Amnesia: The prequel is both this for he and Harry, as they vow never to "let a girl come between them again."
- Anti-Hero: Type I.
- Anticipatory Breath Spray: Except he misses his mouth entirely every single time, at one point causing Eye Scream to Andre who's standing directly beside him. Still has this habit in the sequel.
- Because You Were Nice to Me: Lloyd falls helplessly in love with Mary Swanson because she was one of the only women to talk to him like an everyday person.
- Berserk Button: Harry taps Lloyd's when he "steals" Mary from him.
- Comically Missing the Point: Both have their moments, but Lloyd's got this bad.Harry (after seeing a couple passing by): Holy jeez, look at the butt on that.Lloyd: ...yeah! He must work out.
- Desperately Looking for a Purpose in Life: Shades of this in his speech of why he wants to go to Aspen.
- Did Not Get the Girl: He doesn't get the girl (Mary), and kills her husband in a rage-filled Indulgent Fantasy Segue before leaving quietly.
- The Ditz: Utterly bewilders everyone around him with profound idiocy.
- Drowning My Sorrows: Does this when he believes that Mary stood him up.
- Funny Bruce Lee Noises: Thoroughly parodies and exaggerates this in his Imagine Spot.
- Green-Eyed Monster: After seeing Harry hanging out with Mary.
- Heroes Want Redheads: To Mary.
- Heterosexual Life-Partners: With Harry.
- Hopeless Suitor: Considering that Mary is completely out of his league and creeped out by him...not to mention she's already married.
- Hypocritical Humor: All the damn time.
- I Like Those Odds: "So you're telling me there's a chance?"
- Jerkass: Intentional or not, he easily comes off as the more malicious and unstable of the two.
- Jerk with a Heart of Gold: Despite all of his inane actions throughout the movie, he does mean well and does genuinely care for his best friend Harry.
- Laxative Prank: Lloyd does it to Harry as revenge, since he supposedly stole Mary from him.
- Lethally Stupid: He and Harry accidentally killed Mental, and Lloyd himself blew up a gas station, killed a snow owl with a bottle cork, poisoned Harry with laxatives, nearly got them both killed in a car accident, and shot Mary's husband to death (although the last one was just an imagination sequence). Not to mention the traffic collision he caused in the beginning that ended in a mushroom cloud.
- Malaproper:If I know her [Mary] as well as I think I do, she'll invite us right in for tea and strumpets.I have a rapist's wit.
- He's just spewing these out in the sequel. Too many to count.
- Mistaken for Pedophile/Gibberish of Love: "I desperately want to make love to a schoolboy!"
- Mr. Imagination: Has a big Imagine Spot in both movies.
- Near-Rape Experience: Nearly doubles as Sexual Karma when Sea Bass attempts to rape and kill him in the gas station bathroom as revenge for Lloyd's dine-and-dash scheme.
- Never Learned to Read: Played for Laughs, although oddly enough, Lloyd is unable to pronounce the word "the", but is somehow capable to understand the "We landed on the moon!" clipping. Maybe he needs it in big print.
- Noodle Incident: His romance with Fraida Felcher behind Harry's back is this in the first movie, and the sequel elaborates on this. Turns out both of them were too stupid to fully comprehend how sex works.
- Pet the Dog: He came of as quite insensitive towards Harry in the sequel, but he selflessly gives Harry his kidney, not out of selfishness, but so his friend could be happy and even cries once he realized that the kidney doctor scammed him.
- Psychopathic Man Child: Arguably, considering many of his actions in the movie.
- Red Oni, Blue Oni: The Red to Harry's Blue.
- The Sociopath: Lloyd makes some... questionable actions throughout the movie.
- Stalker with a Crush: To Mary.
- Tacky Tuxedo: An orange one when he and Harry attend the Snow Owl Benefit.
- Trust Me! I'm A Limo Driver!
- Unsympathetic Comedy Protagonist: Due to his more malicious and borderline sociopathic actions, he easily comes off as this.
Harry Dunne (Jeff Daniels)
- Adorkable: The more likable of the two!
- Aesop Amnesia: The prequel is both this for he and Lloyd, as they vow never to "let a girl come between them again."
- Anti-Hero: Type I.
- Big Damn Heroes: Has two of these moments, when he saves Lloyd from being raped by Sea Bass (although this one was unintentional), and at the end, when he fakes his death long enough for the authorities to arrive and arrest the Big Bad.
- Butt-Monkey: Often thanks to Lloyd.
- Comically Missing the Point: Lloyd has it worse, but Harry's still neck-deep in this trope.State trooper: PULL OVER!!!Harry: NO, IT'S A CARDIGAN, BUT THANKS FOR NOTICING!!!
- Disney Death: He appears to have been shot by Andre at the end, but it turns out he was wearing a Bulletproof Vest.
- The Ditz: Just which one's "Dumb" and which one's "Dumber"? As noted below, Harry seems to have more common sense than Lloyd, but is still not very bright for actually going along with Lloyd's schemes.
- Dumb Blonde: Yes, a male example.
- Easily Forgiven: Mary playfully throws snow at Harry, who misguidedly smashes her with a snowball in response. After the resulting chaos is over, Mary laughs it off.
- Extreme Doormat: Throughout the movie, he comes off as a little smarter and more sensible than Lloyd, but for the most part goes along with everything Lloyd does partially because he's just very passive. Although he does lose it and fly off the handle at Lloyd a few times.
- Heroic BSoD: Has one after he realizes that Lloyd backtracked so far east that they no longer had enough gas money to get to Aspen.
- Heterosexual Life-Partners: With Lloyd.
- Imperial Stormtrooper Marksmanship AcademyLloyd: Harry! You're alive! [Beat] ...and you're a horrible shot.
- The Lancer: To Lloyd.
- Laxative Prank: Lloyd does this to him as revenge for "stealing" his girl.
- Lethally Stupid: He accidentally killed Mental by giving him rat poison instead of his ulcer pills (when both he and Lloyd first planted hot peppers in Mental's burger, ultimately causing Mental's ulcer to burst).
- Luke, I Am Your Father: In the sequel, Harry finds out that he's a father to a daughter he sired with Fraida Felcher... back in 1991. Or so he thinks.
- Malaproper:Harry: I thought we were gonna be together forever. Then about a week later, right outta the blue, she sends me a John Deere letter.
- Manchild: Has the humor and maturity of a teenager. Even in the sequel!
- Messy Hair: Which befits his character perfectly.
- Nice Guy: His stupidity may lead to some unintentional jerkass moments, but Harry's a well-meaning guy in general and an especially good friend to Lloyd.
- Potty Emergency: In a particularly infamous scene, thanks to the Laxative Prank, Harry takes one of the most grandiose dumps in the history of cinema.
- Red Oni, Blue Oni: The Blue to Lloyd's Red.
- Tacky Tuxedo: A blue one when he and Lloyd attend the Snow Owl Benefit.
- Tranquil Fury: When Lloyd reveals he's been wearing extra gloves the whole time while Harry's hands were freezing, on top of the other things Lloyd did to him up to that point, he laughs and tells Lloyd he's going to kill him, and starts to follow through with the task.
Mary Swanson (Lauren Holly)
- Damsel in Distress: Held at gunpoint in the climactic scene, and Lloyd is in no position to save her - he's right next to her.
- Ms. Fanservice: In the "Aspen dream sequence."
- Nice Girl: Actually a very kind and levelheaded woman, and very patient with Harry and Lloyd's antics. No wonder they both become attracted to her.
- Only Sane Woman: Between two utter imbeciles and a lying, manipulative kidnapper.
- Punny Name: Averted, if she and Lloyd had ended up together, her name would have been "Mary Christmas."
- Relationship Reveal:Lloyd: Husband?! Wait a minute! What was all that one-in-a-million talk?
- Stepford Smiler: Convinced into this by her family to keep up appearances.
- Straight Woman: For Harry and Lloyd.
Joe "Mental" Mentalino (Mike Starr) and JP Shay (Karen Duffy)
- Asshole Victim: In the restaurant scene, where he gets poisoned.
- Bad People Abuse Animals: Joe kills Harry's parakeet to send a message to Lloyd and Harry.
- Butt-Monkey: Poor Mental gets annoyed to death and is eventually on the receiving end of Harry and Lloyd's antics.
- Co-Dragons: To Andre, with Mental appearing to be the favoured one.
- Death by Irony: From the rat poison he was about to put in their drinks.
- Even Evil Has Standards: See quote.
- JP is shocked when Joe kills Petey, Harry's parakeet.
- Famous Last Words: Mental grunts out "SON OF A....BITCH..." before succumbing to poison. Unless you count the gurgling...
- HeelFace Door-Slam: Mental finally learns that Harry and Lloyd did not intentionally steal the briefcase and are just two lovesick losers with too much time on their hands just before they accidentally poison him.
- Hoist by His Own Petard: Mental dies after accidentally taking the rat poison he intended to spike Harry and Lloyd's drinks with.
- Jerkass: Both of them are just scowling thugs to everyone around them.
- Tomboy: JP. It's almost a shock to see her later in a dress.
- Kick the Dog: RIP, Petey.
- Pet the Dog: Mental decides to spare Harry and Lloyd after learning they stole the briefcase by accident.
Nicholas Andre (Charles Rocket)
- Big Bad: Of the first film.
- Deadpan Snarker: Any attempts at humor on his part are out of sheer frustration.
- Evil Is Hammy: The more he gets pissed off, the more he's this. He's pissed off a lot.
- Hot-Blooded: Big time.
- I Have Your Husband: Kicks off the plot with this. It goes slightly awry thanks to the dimwitted duo.
- Knight of Cerebus: Charles Rocket plays him almost totally straight, which in this kind of movie actually makes him a really intimidating presence.
- Man of Wealth and Taste: Usually seen dressed to the nines.
- Surrounded by Idiots: Just completely done with everyone's shit for much of his screentime.
Sea Bass (Cam Neely)
- Ambiguously Bi: If his cap is any indication, he's into women too.
- Asshole Victim: He doesn't die, but deserves all of the hell he is put through.
- Attempted Rape: Not only that but he also planned to kill Lloyd.
- Catchphrase: From his friends: "Kick his ass, Sea Bass!"
- The Cameo: After the end credits of the sequel.
- The Door Slams You: How Harry saves Lloyd from the Attempted Rape.
- Grumpy Bear: He only has a handful of scenes, but he is never shown in a good mood.
- Hair-Trigger Temper: He's always pissed.
- Have I Mentioned I Am Sexually Active Today?: Sea Bass wears a cap that says "Wine Em, Dine Em, 69 Em". Made all the more ironic by the fact that he solicits gay sex in gas station bathrooms.
- Jerkass: Has virtually no redeeming aspects at all.
- Laser-Guided Karma: Harry and Lloyd pulling a dine and dash on him, and then Harry slamming him in the face with a bathroom stall door.
- Manly Gay: As manly as it gets!
"Athletic Beauty" a.k.a. Special Officer Beth Jordan (Victoria Rowell)
- Motor Mouth: Talks Lloyd's ear off about her boyfriend while he's waiting in the bar. He hates this.
- Obfuscating Stupidity: Has conversations with both Harry and Lloyd, and gives off a seriously ditzy vibe until The Reveal at the climax.
- "Shaggy Dog" Story: Her stories about her boyfriend to an uncaring Lloyd.
- Undercover Cop Reveal: Turns out she's an FBI agent, who, with other members of the force, has been following the guys all the way from Providence.
Billy in 4C (Brady Bluhm)
- Butt-Monkey: Lloyd sells him a dead bird with its head taped on, likely scarring him for life.
- Kindhearted Bird Lover: Especially in the sequel, where he's grown up and owns several birds, which then get eaten by Harry's cat.
- Insistent Terminology: He's always referred to by the number of his apartment, although without subtitles on, it's easy to think this means his last name is "Enforcee".
Dr. Bernard Pinchelow (Steve Tom)
Adele Pinchelow (Laurie Holden)
- Big Bad: Of the sequel.
Fraida Felcher (Kathleen Turner)
Travis and Captain Lippencott (Rob Riggle)
- The Dragon: For Adele Pinchelow.