A country dog who wants to become a musketeer.

• Badass Adorable: Dogtanian is an adorable young pup, who is also an excellent swordsman. Several times, he is shown to be capable of beating older and more experienced opponents.
• Bratty Half-Pint: Mostly at the start of the story, Dogtanian tends to act like a brat. In his hometown, he was considered a Toxic Friend Influence for the other kids.
• Country Mouse: A poor kid from the country who moves to Paris. He doesn't like being insulted for his origins.
• Determinator: Dogtanian always fights to achieve his objectives, like joining the Musketeers and saving Juliette's life.
• Genius Ditz: As lampshaded by Pip, Dogtanian is not the smartest dog, but he is still a brilliant swordsman.
• Hot-Blooded: Dogtanian gets angry rather easily, and is initially described as a "hothead".
• Jerk with a Heart of Gold: Despite his ego and brash tendencies, he is still a heroic puppy who cares about his friends (especially the other Musketeers and Pip), and deeply loves Juliette.
• Like Father, Unlike Son: According to Monsieur de Treville, Dogtanian's father was humble and level-headed. He is surprised that Dogtanian himself is so boastful and Hot-Blooded.
• Kid Hero: Dogtanian is the only Muskehound cadet who gets to hang out with the fully-fledged Musketeers.
• Master Swordsman: He is easily able to beat older swordsmen, occasionally fighting many of them at the same time.
• Pint-Sized Powerhouse: Despite being much smaller than most of the other characters, Dogtanian is a powerhouse with his sword in battles.

The leader of the three Musketeers.

• Adaptation Personality Change: In the original story, Athos was The Leader and Porthos was The Big Guy. Here, their personalities are switched.
• Clear My Name: In Episode 4, the heroic Porthos was framed as a criminal because a thief was impersonating him. This is resolved at the end of the episode.
• Master Swordsman: Porthos is considered one of the best swordsmen in the Corps.
• Standardized Leader: He is the leader of the Musketeers, and has the least amount of defining traits compared to the others, aside from being very disciplined.
• Supporting Leader: Despite Porthos being the leader, Dogtanian is the main character. It helps that Dogtanian joined the Musketeers later.

The strongest of the Musketeers.

• Adaptation Personality Change: In the original story, Athos was The Leader and Porthos was The Big Guy. Here, their personalities are switched.
• Boisterous Bruiser: The rowdy and extroverted Big Guy of the Musketeers, and he also enjoys showing off in front of the citizens.
• Fat Comic Relief: Athos is the only overweight Musketeer, as well as a comic relief character compared to the relatively serious Porthos and Aramis.
• Hair-Trigger Temper: He is more quick to anger than the other Musketeers, aside from Dogtanian himself in early episodes. Sometimes, Porthos and Aramis try to calm him down.
• Stout Strength: Athos is visibly overweight and proud of his Super-Strength.
• World's Strongest Man: He is stated to be the strongest man in France since his first appearance.

The most romantic of the Musketeers.

• Badass Bookworm: He is shown reading a book in his Establishing Character Moment, while also being a badass swordsman.
• The Charmer: Aramis is a romantic ladies man who loves women and treats them very politely.
• Cultured Badass: The sophisticated, polite, and intellectual member of the Musketeers. He enjoys books and religion, and respects fine women.
• Master Swordsman: Aramis is one of the best swordsmen in France. He can hold his own in a battle with the very skilled Rochefort.
• Token Religious Teammate: He reads his Bible in episode 4 when he meets Dogtanian, while the others don't mention religion very often.

Dogtanian's love interest.

• Adaptation Name Change: She is based on Constance Bonancieux from the novels.
• Damsel in Distress: Juliette is kidnapped by Rochefort, and is targeted by the villains more than once.
• Damsel out of Distress: After Dogtanian's rescue attempt fails, Juliette escapes on her own, and she even hits Rochefort's minion on his head. Later, she is able to escape from Milady who also wanted to threaten her.
• Hair of Gold, Heart of Gold: Juliette has blonde hair and is always nice, to the point that she apologizes to the criminal after hitting him in self-defence.
• Lady in Waiting: Works as the lady-in-waiting and confidant to Queen Anne.
• Pink Means Feminine: She wears a pink dress, and serves as the Light Feminine to Milady's Dark.
• Related Differently in the Adaptation: In this story, she is M. Bonacieux's niece rather than his wife like in the novels.

A mouse who follows Dogtanian in later episodes.

• Adaptation Name Change: He's called Pom in the original Spanish version.
• Big Eater: During the trips, he often complains because he is hungry and there is nothing to eat.
• Canon Foreigner: An original character who has no equivalent in the novel.
• Deadpan Snarker: He has a big sarcastic streak, especially when he makes fun of Dogtanian and the villains.
• Nice Mice: Despite being a snarky and mischievous mouse, Pip is very loyal to Dogtanian. He becomes more selfish in the 2021 movie, though.
• Plucky Comic Relief: Pip is introduced in the second half of the story to act as the funny sidekick for the hero, after Dogtanian himself becomes more serious and less impulsive.
• Shipper on Deck: He supports Dogtanian and Juliette, often teasing Dogtanian about Everyone Can See It.

The Captain of the Musketeers.

• Reasonable Authority Figure: To the Musketeers. When he has to select a new member, he values honor and loyalty over their status.
• Undying Loyalty: Treville is utterly loyal to the King, and fought to defend France in the past.

The Prime Minister of France.

• Arch-Enemy: To Monsieur de Treville and the Musketeers. Richelieu is against them because he wants his own guards to have full control of the palace.
• Big Bad: The main antagonist and the source of the main conflict. The other bad guys work for him.
• Evil Chancellor: Richelieu acts as an advisor to the King, while also manipulating him and trying to put him against Treville and his guards.
• Foul Fox: He is the main villain and the only character portrayed as a fox.
• Villain with Good Publicity: Cardinal Richelieu serves the King, just like Monsieur de Treville. The King trusts them both, initially.
• Wouldn't Hurt a Child: Hurting children is where Richelieu draws the line, even if they're Dogtanian's kids.

Richelieu's henchman who often fights against Dogtanian.

• The Dragon: Count Rochefort is the Cardinal's henchman-in-chief for non-spy work (Milady handles the latter).
• Even Evil Has Standards: Although a loyal servant of the evil Richelieu, Rochefort is disgusted by Richelieu and Widimer wanting to poison Dogtanian at the end. He even goes to warn Dogtanian.
• Genius Bruiser: Rochefort is the most cunning of Richelieu's henchmen, while also being a very good swordsman.
• Hyper-Competent Sidekick: To Richelieu. In contrast to the inept Widimer, Rochefort is a much more competent minion. That's why Richelieu trusts him more, much to Widimer's chagrin.
• Master Swordsman: Like the Musketeers, Rochefort has excellent sword skills.
• Noble Demon: He turns out to be a man of honour. In the final episode, he personally tips off Dogtanian about Richelieu and Widimer's plot to poison him because he feels killing a cavalier in such an underhanded manner would violate the Code of Honour, challenging Dogtanian to a duel at the same time.
• Worthy Opponent: Rochefort is a skilled and competent adversary to the Musketeers, and also has his own honour code.

The captain of Richelieu's Guards.

• Authority in Name Only: Despite being the captain, not even the other guards respect him. It's clear that they only see Richelieu as their real boss.
• Fat Bastard: The most overweight of the villains, and probably the biggest jerk of them all. Widimer has no sympathetic traits.
• Karmic Butt-Monkey: A lof of his antagonism backfires on him, and he collects humiliating defeats all the time.
• Laughably Evil: Widimer is definitely evil and willing to hurt people without remorse, but is also ridiculously inept at almost everything.
• Not-So-Harmless Villain: While he is the least competent minion of Cardinal Richelieu, Widimer is perfectly capable of murder. In his debut episode, he shoots the Porthos impersonator, killing him.
• Small Name, Big Ego: Widimer likes to think of himself as the top minion of Richelieu, but he is too incompetent for it.

Another spy for Cardinal Richelieu.

• Adaptational Badass: While she is shown to be good at hypnosis via trance, she has a magic necklace in the movie that hypnotizes anyone who looks at her; she's also a lot better at combat.
• Adaptational Jerk Ass: While in the series, whenever she had encounters with Dogtanian, she mainly didn't fight him much at all, in the movie she also takes over Rochefort's service role during Dogtanian's duel with Rochefort, where she hits Dogtanian on the head.
• Cats Are Mean: As a feline, Milady is notably more devious than the other baddies.
• Even Evil Has Standards: In the sequel, Milady doesn't hesitate to take Blanc Bec's offer to help him set a trap against Dogtanian by kidnapping Fleur, Dogtanian's daughter. But when he decides to take drastic actions by ordering her to cut Fleur's finger and send the blood in a written ultimatum to Dogtanian, she decides to stop helping him and tries to run away with her.
• Light Feminine and Dark Feminine: As the manipulative Femme Fatale, she is the Dark Feminine to Juliette's sweet and innocent Light Feminine.
• Sexy Cat Person: Milady is one of the few cats in the cartoon. Though cloaked, her voice and mannerisms serve this trope, and the other characters find her attractive.
• Spared by the Adaptation: Her character was executed by beheading in the original Dumas novel. Here, she survives and even returns in the sequel