Main •
Anton Yelchin (episodes 1–41) and
Emile Hirsch (episodes 42–52) as James "Jim" Lake Jr. / Trollhunter, the first human Trollhunter and a
reluctant hero dealing with the pressures of leading a double life and being a normal teenager. He is friendly, honorable, brave, heroic, and cares a great deal about his mother and friends. Jim is also highly skilled at
cooking, often preparing impressive meals for his mother and friends, especially Toby. Yelchin provided the voice of Jim from Part 1, through portions of Part 3 before his death. Hirsch assumed the role and replaced him. •
Charlie Saxton as Tobias "Toby" Domzalski, Jim's male best friend and confidant, an overweight
Polish-American boy who lives with his grandmother. Dorky and excitable, he fully embraces the secret world of trolls and eagerly aids Jim in his quests. His weapon of choice is a
warhammer. • Lexi Medrano as Claire Maria Nuñez, Jim's female best friend/girlfriend, a feisty, irritable yet friendly and warm-hearted
Mexican-American girl who is a talented
martial artist and
gymnast, using her skills to aid Jim in his quests. She obtains the Shadow Staff (Skathe-Hrün), a
staff capable of creating portals activated by the user's emotions. •
Kelsey Grammer as Blinkous "Blinky" Galadrigal, Jim's six-eyed four-armed troll mentor. A wise and scholarly troll with a heart of gold, he serves as the brains of the Trollhunters and eventually becomes a sort of father figure to Jim. •
Jonathan Hyde as Waltolomew ‘Walter’ Stricklander ‘Strickler’, Jim's history teacher who is actually a Changeling. When Jim discovers the truth, in
Young Atlas, he loses all respect for him and the two become bitter enemies. However, he remains affable toward Jim and has redeeming qualities. •
Fred Tatasciore as Aarghaumont "AAARRRGGHH!!!", a burly troll and close companion of Blinky, who forms a deep bond with Toby. He was kidnapped by the Gumm-Gumms as a child from the Krubera (a race of troll that lives deep in the earth) which stunted his vocabulary. Tormented by the atrocities he committed, he deserted Gunmar to live a life of peace (as shown in
Wizards). However, he will still fight to protect those he cares about. •
Victor Raider-Wexler as Vendel, the leader of Trollmarket. An ancient and wizened troll, Vendel is at first suspicious of Jim and often comes across as a pessimist, but shows a softer side and eventual faith in Jim. At the end of Part 2, he is killed by Usurna after she reveals herself to be working for Gunmar, but not before recording the act to warn the Trollhunters. •
Ron Perlman as Bular, the son of Gunmar. A brutish and powerful troll warrior, he is obsessed with freeing his father from the Darklands. He holds a special disdain for Changelings, whom he considers "impure", putting him at odds with Strickler and other Changelings who seek to free Gunmar. He is killed by Jim in the first half of season 1, but later makes appearances in the season 1 episode "Where Is My Mind?" and the season 2 episode "Unbecoming". •
Clancy Brown as Gunmar, the iron-fisted leader of the Gumm-Gumms who reside in the Darklands. He is powerful and ruthless, and will readily dispose of loyal minions and allies who can no longer serve him. He has no qualms about enslaving or killing his fellow trolls to accomplish his goals. However, he cares deeply for his son, Bular. Despite his apparent main antagonist role, Gunmar in fact serves Morgana. •
Amy Landecker as Barbara Lake, Jim's protective and overworked single mother. Her husband left the family when Jim was five years old. Her job as a doctor means she's often away from home, which lets Jim pursue his Trollhunter duties. Jim's impressive cooking skills are most likely out of neccessity as Barbara herself is bad at cooking. •
Steven Yeun as Steve Palchuk, a narcissistic
jock who frequently bullies Jim. Suspicious of Jim's unusual behavior, he eventually discovers the truth and teams up with Eli Pepperjack becoming the Creepslayerz to help Jim in Part 2. •
Cole Sand as Eli Pepperjack, a nerdy classmate of Jim who believes in the
paranormal. In Part 2, he teams up with Steve Palchuk to investigate the strange creatures they both have seen and to help Jim.
Recurring • Matthew Waterson as Draal, the son of previous Trollhunter, Kanjigar. He is originally jealous and suspicious of Jim but later befriends him – acting as Jim's fighting tutor. During a battle in the museum, Draal sacrifices his lower right arm while removing the Trollhunter amulet from the Killahead Bridge to close the portal, and later obtains a mechanical
prosthetic. Draal explains that his father kept a distance from him as he grew up, and he had hoped to become the next Trollhunter that he might earn his father's approval. He was killed by Angor Rot in season three. •
Lauren Tom as Nomura, the Changeling museum curator and a colleague of Strickler. Originally an antagonist, she was pulled into the Darklands and imprisoned by Gunmar for her failures. When Jim is captured in the Darklands, the two form a connection and escape together. • Jimmie Wood as NotEnrique, the Changeling swapped with Claire's baby brother Enrique. While troublesome and self-serving, he isn't actively malicious and even helps the Trollhunters from time to time (usually after being bribed). He forms a rocky but brotherly connection with Claire. •
Tom Hiddleston and
James Purefoy as Kanjigar the Courageous, Draal's father and the noble Trollhunter prior to Jim. His ghost tutors Jim, often worrying about Jim's team fighting style, believing that the Trollhunter must work alone to avoid endangering those he cares about – this leads to Jim's guilt and decision to venture into the Darklands alone. Hiddleston provided the voice acting for Kanjigar during the series premiere, while Purefoy was cast to assume the role for the rest of the series. •
Ike Amadi as Angor Rot, an ancient troll assassin who hunts down Trollhunters and takes their souls. In medieval times, Angor made a deal with Morgana, surrendering his own soul in return for his mystical powers. • Rodrigo Blaas as
Gnome Chompsky, a Gnome adopted by Toby. He started out as a "rogue Gnome" causing trouble, but after he was finally defeated by Jim he became friendly when he was given a dollhouse to live in and a plastic doll to be his companion. He later helps locate Enrique in the Darklands and also helps rescue Jim from the Darklands. •
Mark Hamill as Dictatious Galadrigal, Blinky's brother. Presumed dead, he helps Gunmar in his quest to conquer the surface lands. He is blinded by Blinky during a struggle in the Darklands. •
Anjelica Huston as Queen Usurna, the queen of the Krubera, AAARRRGGHH!!!'s race of trolls who lives in the Deep Caverns, and a member of a council of troll leaders known as the Tribunal. She initially seems to be a kind queen concerned for AAARRRGGHH!!!'s well-being. As a Tribunal member, she is strict and judgmental and leads the Tribunal to act against Jim and his friends. Late in Part 2, she reveals herself to be a traitor who works for Gunmar and helps him take over Trollmarket. •
Lena Headey as
Morgan le Fay, an ancient and seemingly malevolent entity and the patron of Angor Rot. •
Laraine Newman as Lenora Janeth, the algebra and drama teacher of Arcadia Oaks High. •
Tom Kenny as Otto Scaarbach, a Changeling Polymorph who can change into the form of anyone. He is the Grand Commandant of the Janus Order, a secret society of Changelings who assist the Gumm-Gumms. He also voices Claire's father, Javier Nuñez, and Dadblank in 3Below and Rise of the Titans. •
David Bradley as
Merlin, the wizard who created the Trollhunter's amulet. •
Colin O'Donoghue as Hisirdoux "Douxie" Casperan, a charming English teen from Arcadia Oaks Academy whose band, "Ash Dispersal Pattern", is an entrant in the Battle of the Bands in Part 3. In Rise of the Titans he is a major character, and a former apprentice (now he is a master wizard) to Merlin. •
Tatiana Maslany as Aja, a "foreign exchange student" from "
Cantaloupia" and older sister to Krel. Jim is tasked to show them around and acclimate them to Arcadia late in Part 3. The character (alongside Krel) returns in Rise of the Titans. •
Diego Luna as Krel, younger brother to Aja. The character (alongside Aja) returns in Rise of the Titans. •
Yara Shahidi as Darci Scott, Jim, Toby and Claire's classmate. == Production ==