King Arthur
- I am Arthur! King of the Britons! And I NEVER refuse a challenge!Voiced by Rik Mayall
- All Love Is Unrequited: With Guinevere.
- Butt-Monkey: No matter how he tries, Guinevere always comes up with some reason why his effort to complete her latest quest isn't enough.
- Character Catchphrase: "OH EXCELLENT!" and "I have a plan of unspeakable ingenuity".
- Closest Thing We Got: Merlin has noted that Arthur is a "wise, just and well-loved king [..] considering the alternatives".
- Color-Coded for Your Convenience: Red is his signature color.
- Deadpan Snarker: Has his moments.
- Hair Color Dissonance As a kid, his hair started out more outright blonde while fading to dirty caramel blonde.
- Raised by Wolves: For whatever reason, he's been raised by monkeys in the forest.
- Ungrateful Bastard: Thinks Sir Margaret is "too aggressive" despite her saving his ass so many times.
Merlin
- DARK FOOOOORCES!Voiced by Matt Lucas
- Butt-Monkey: Forced to accompany Arthur on all of his desperate quests.
- The Cassandra: Warns Arthur about the dangers of his quests. But does Arthur listen?
- Character Catchphrase: DARK FOOOOOOORCES!
- Color-Coded for Your Convenience: Wears orange.
- Deadpan Snarker: Has his moments.
- Inept Mage: Despite his traditional mythological reputation, this Merlin has a reputation of being a bad wizard that extends as far as Spain.
- Supportive Snarker: While Arthur's actions can be frustrating, Merlin is consistently loyal.
Princess Guinevere
- "Because I want to be the only princess in the kingdom with a Yodeling Dolphin! Let's face it, my goldfish doesn't do anything exciting!"Voiced by Morwenna Banks
- Girl in the Tower: Subverted as she's not trapped-she lives in her own tower that she never leaves unless if she's escorted by someone.
- It's All About Me: Most of the time her requests to Arthur are just based around her desire to have some new trend or indulge a relatively minor whim.
- Rich Bitch: She lives in her own palace; enough said.
- Spoiled Brat: Some quests are based around very fundamentally petty concerns, such as her not wanting to get any older.
- Upperclass Twit
Sir Lancelot
- "Oh, Merlin it's been awhile. You look different. Have you had a wash?Voiced by Phil Cornwell
- Character Catchphrase: "Oh blow!" Yeah you read that right.
- Chronic Backstabbing Disorder: Consistently attempts to use the latest quest as an opportunity to get rid of Arthur.
- Groupie Brigade Has quite a few ladies following him around
- Spell My Name With An S: Most promotional material lists him as "Sir Launcelot."
- Vitriolic Best Buds: Him and Martyn are either collaborating or backstabbing one another.
- We Used to Be Friends: With Arthur (although he was overly competitive with Arthur even as children)
Lady M./Sir Margaret
- "Helpless? Well we'll see about that!"Voice actor unknown.
- Berserk Button: Don't underestimate her because she's a girl. Also don't ruin her rosebuds.
- Sibling Yin-Yang: With Arthur
- Foolish Sibling, Responsible Sibling: The responsible sibling to Arthur's foolish.
- Waif-Fu: A thin woman who is nevertheless a skilled fighter.
Robin Hood
- "Heheheheheh."Voiced by Phil Cornwell
- Animals Hate Him: He tried to be a friend to all animals, but tends to get mauled.
- Character Catchphrase: "LET ME TELL YOU THE TALE OF ROBIN HOOO*gets cut off*"
- The Friend That Nobody Likes: His merry men and women don't care for his excess optimism.
- Signature Laugh: "Hehhehehehe".
Sir Martyn the May Tin Gong
- "It'll take more than that to deter me, Lancelot."Voiced by Matt Lucas.
- Spell My Name With An S: His name is unconventionally spelled with a Y.
- Vitriolic Best Buds: With Lancelot. They're either collaborating or trying to kill each other.
Splag
- Flursh yurkurt.Voiced by Phil Cornwell.
- Acrofatic: Fat but physically powerful.
- Aerith and Bob: The only one who's name is a non-sequitor.
- The Big Guy: The largest character in the show.
- The Unintelligible: He was once shown to speak 'Moonish' (actually Welsh), but in general he cannot be understood when he speaks. .