List of Ben 10 characters

This is a list of characters in the universe of the Cartoon Network's Ben 10 franchise.¹²

• This table shows the recurring characters and the actors who have portrayed them throughout the franchise.
• A dark grey cell indicates the character was not in the series or film, or that the character's presence in the series or film has not yet been announced.
• A ^Y indicates an appearance as a younger version of a pre-existing character.
• A ^C indicates a cameo appearance.
• A ^P indicates an appearance in onscreen photographs only.
• A ^D indicates an appearance in deleted scenes only.
• A ^M indicates a motion-capture role.
• A ^U indicates an uncredited role.

  = Main cast

  = Recurring cast

  = Guest cast

• This table shows the recurring characters and the actors who have portrayed them throughout the franchise.
• A dark grey cell indicates the character was not in the series or film, or that the character's presence in the series or film has not yet been announced.
• A ^Y indicates an appearance as a younger version of a pre-existing character.
• A ^C indicates a cameo appearance.
• A ^P indicates an appearance in onscreen photographs only.
• A ^D indicates an appearance in deleted scenes only.
• A ^M indicates a motion-capture role.
• A ^U indicates an uncredited role.

Voiced by:

• Tara Strong – Ben 10 (2005), Ben 10: Ultimate Alien, Ben 10: Omniverse & Ben 10 (2016) (child)
• Yuri Lowenthal – Ben 10: Alien Force, Ben 10: Ultimate Alien, Ben 10: Omniverse & Ben 10 (2016) (teenager)

Portrayed by:

• Graham Phillips – Ben 10: Race Against Time
• Ryan Kelley – Ben 10: Alien Swarm

Ben Tennyson is the titular character and the main protagonist of the franchise. At the start of Ben 10, he is a 10-year-old boy^{note 1} from Bellwood who, during his summer vacation, discovers the Omnitrix, a prototype device that attaches to his wrist and allows him to transform into various aliens. He uses the Prototype Omnitrix to become a hero while traveling across the USA. After the Prototype Omnitrix is self-destroyed at the end of Alien Force, Ben retrieves the Ultimatrix from Albedo and uses it as a replacement. At the end of Ultimate Alien, Azmuth takes the Ultimatrix away to destroy and gives Ben the Completed Omnitrix.

Voiced by:

• Meagan Smith – Ben 10 (2005)
• Ashley Johnson – Ben 10: Alien Force, Ben 10: Ultimate Alien, & Ben 10: Omniverse
• Montserrat Hernandez – Ben 10 (2016)

Portrayed by:

• Haley Ramm – Ben 10: Race Against Time
• Galadriel Stineman – Ben 10: Alien Swarm

Gwen Tennyson is Ben's paternal cousin. In the original series, Gwen shared a love-hate family relationship with Ben. Before discovering and reinventing her dormant magic powers, she helped Ben using her innate intelligence; she is also a talented martial artist who has received black belts in karate and taekwondo. Gwen is a model student, and in Omniverse, she is shown leaving for an Ivy League College.

Gwen is able to manipulate mystical energy named "mana" to create energy blasts, shields, and other constructs. She later learns that her powers are not magic in origin, but rather alien, and her paternal grandmother, Verdona, is a powerful Anodite alien who can manipulate mana, the essence of magic and life.³ Gwen cannot take on a fully Anodite form at will unless she masters it.

Voiced by:

• Paul Eiding – Ben 10 (2005), Ben 10: Alien Force, Ben 10: Ultimate Alien & Ben 10: Omniverse (adult)
• Adam Wylie – Ben 10 (2005) (child)
• Jason Marsden – Ben 10: Ultimate Alien (teenager)
• David Kaye  – Ben 10 (2016)

Portrayed by:

• Lee Majors – Ben 10: Race Against Time
• Barry Corbin – Ben 10: Alien Swarm

Max Tennyson is Ben and Gwen's paternal grandfather. He is 60 years old in the original series, 65 in Alien Force and the reboot, 66 in Ultimate Alien and Omniverse, 80 in Ben 10,000 and 92 in Ken 10.^{note 2} Despite his age, he is shown to be an experienced capable fighter, and after Ben finds the Omnitrix, supports him any way he can. Max was once a candidate for the Apollo 11 mission and one of the leaders, or "Magisters", of the Plumber organization, but Ben and Gwen did not know of this at first, believing him to have been a literal plumber.

Kevin Levin (voiced by Michael Reisz in the original series episode "Kevin 11", Charlie Schlatter in later episodes of the original series, and Greg Cipes in subsequent series; portrayed by Nathan Keyes in Alien Swarm) is initially depicted as an Osmosian with the ability to absorb matter, energy, and DNA and initially appears in the original series as an 11-year-old^{note 3} boy and one of Ben's enemies.⁴ Believing his stepfather Harvey Hackett convinced his mother to abandon him after he accidentally destroyed his family's house when his powers first manifested, Kevin ran away and ended up living in the subway of New York City, where he met Ben and used him to siphon the Omnitrix's energies to get back at those who demonized him. However, Kevin was also infused with the DNA of the aliens Ben had access to at the time and became a chimeric hybrid of the alien forms, which rendered him psychotic and unstable. Kevin managed to return to his original form after being trapped in the Null Void. In Omniverse, it is revealed that Kevin is actually a human and derived his powers from a genetic mutation.

In the reboot, Kevin is a human who wields the Antitrix, a version of the Omnitrix that allows him to transform into modified versions of Ben's aliens.⁵

Rook Blonko (voiced by Bumper Robinson) is a Revonnahgander Plumber who Max assigns to work with Ben after Gwen and Kevin leave Bellwood for college. Rook is a top Plumber Academy graduate and skilled fighter who wields the Proto-tool, a shapeshifting weapon that can transform into various tools.⁶

Professor Paradox (voiced by David McCallum) is a time traveler who received government funding to work on breaking a hole in the space-time continuum during the Cold War. A miscalculation caused Paradox to get sucked into the Event Horizon, where he remained displaced from time for 100,000 years. Losing his mind and regaining his sanity, he gained a complete understanding of the space-time and renamed himself Paradox. Paradox uses the Chrononavigator to traverse space and time, which initially appears in the series as a pocket watch.⁷

Ben 23 (voiced by Tara Strong) is a rich and younger version of Ben from Dimension 23, being a celebrity in his universe with his own agent. In contrast to Ben, Ben 23's alien transformations are predominantly blue rather than green and have different names than Ben Prime. Making his debut in "Store 23" when Ben ended up in Dimension 23, Ben 23 is revealed to only got the Omnitrix after his universe's version of Max Tennyson died. As a result, Ben 23 taught himself how to use the Omnitrix while on the notion that all aliens are evil. The prime timeline Ben's interference allows Ben 23 to understand that not all aliens actually are evil.

Ben 10,000 (voiced by Fred Tatasciore in the original series and reboot, Sean Donnellan in Ultimate Alien, Judd Nelson in Omniverse) is the future version of Ben. The original version of the character is named for his expanded roster, consisting of 10,000 aliens.⁸

One of Ben's love interests debuting in Alien Force.

Ben's first love interest, current girlfriend and future wife.

A Galvin who create the Omnitrix.

Vilgax (voiced by Steve Blum in the original series and Omniverse, James Remar in Alien Force and Ultimate Alien, Yuri Lowenthal in the reboot) is a Chimera Sui Generis warlord who is Ben's first and most recurring arch-nemesis through the series. Vilgax was exiled from his home world for being ruthless, cruel, and power hungry. Soon after, Vilgax learned of the Omnitrix's existence after being attacked by George Washington and a time-traveling Ben. Vilgax became determined to have the Omnitrix and use it to build an army for his use.

A mad scientist who experiments on animals and one of Ben's first human enemies.

A mythical wizard who has clashed with Ben and Gwen on various encounters.

Hex' niece who is gwen's arch-rival in all incarnations of the franchise.

A group of high tech knights determined to stop any alien invasions. In the Reboot there was only one forever knight who is a robot.

An ectonurite who was the basis for Ghostfreak until he escaped and became Ben's terrific enemy.

Zs'skayr's right hand man.

An alien who serves under Vilgax.

An alien bounty hunter that fights Ben on sereval instatences.

A former Apprentice of Azmuth turned into a clone of Ben.

A son of a Plumbmer who has energy absorption and became darkstar.

An supernatural evil Clown who can absorb life force from his victims.

A man with lose teeth and leader of the Circus freak trio.

The Muscleman of the Circus freak trio.

A woman who uses tentacle hair. In the reboot she is a child.