Main •
Dennis (voiced by
Richard Pearce) is the main character, a troublemaker and mischievous young boy. While most of it is for fun, his mischief can sometimes cause serious problems, or even help others. Dennis' antics have caused him to gain multiple enemies including his next-door neighbour Walter, the Colonel, and Sergeant Slipper. Dennis has saved the world on one occasion and appeared on
Blue Peter after winning an art competition ("The Competition"). One of his favourite TV shows is "
Nick Kelly" (a character who featured in another
D.C. Thomson & Co. comic). •
Gnasher (voiced by
Kerry Shale) is Dennis's pet dog, an Abyssinian wire-haired tripe hound. He is Dennis's "partner in crime". Twenty-four hours a day, seven days a week together they are the proverbial "two peas in a pod". When he's not by Dennis's side, like during school hours (though he does follow Dennis to school in the mornings), Gnasher will have taken up his vigil, hiding in the front garden, ready and waiting to ambush the postman as he attempts to deliver the mail on Gnasher's watch. Gnasher's family still lives on the isle of Abyssinia, as revealed in "The Trial", when a company had accused Gnasher of being a rat. Gnasher possesses a set of teeth that are capable of chewing through almost anything, hence his name. His favourite food is bones, and his favourite dog toy is his squeaky bone. In "Summer Holiday", Gnasher went by the alias of 'Norman' – in order to pass himself off as a baby to help the family find lodgings at a hotel that forbids pets. In "Special Agent Dennis", it's revealed that Dennis feeds Gnasher his homework rather than actually do the homework. • Dennis' Dad (voiced by
John Baddeley) is under a lot of stress due to Dennis' mischief; he often tries to discipline his son, with few results, and is forced to resort to extreme measures at times. He works in an office. • Dennis' Mum (voiced by
Eve Karpf) seems to be able to cope more with Dennis' behaviour and on equal terms, Dennis listens to her when she reprimands him. At times, she can be rather oblivious to events around her and silly, using household objects to help her when she takes driving lessons ("Menace Power"). • Dennis's Granny, Gertrude (voiced by
Sally Grace) Although she is eight decades old, Dennis's Granny is still very young at heart. Dennis loves his Granny, defends her when another speaks ill of her ("Dennis and the Beanstalk"), and will come to her for advice in times of need ("The Secret Diary"). In her youth, Dennis's Granny was every bit the Menace towards anything like a peaceful society in Beanotown that her grandson is today, as revealed in "The Secret Diary", and in her day there was a police officer, Sgt. Boot, who was the "Sgt. Slipper" to her "Dennis". According to
information from the Beano comic, she is the mother of Dennis's Dad; in "The Secret Diary", when Dennis's Dad mentions more than once how well-behaved he was to his parents, he may have been referring particularly to his father because Dennis's Granny favours her grandson, Dennis, who takes after her. In "The Secret Diary", she was depicted as having black hair, like her son and grandson, but in "Gorilla Warfare", she was seen in a
flashback with blond hair (so possibly she dyed it). She rides a motorcycle and eats pizza with "everything on them". She is perhaps the only adult, as mentioned by Dennis's Dad, "insane enough" to provide Dennis with any adult supervision and survive intact; she will even willingly come back for more of the fun and mayhem. • Curly (voiced by
Jill Lidstone) is Dennis's best friend and fellow Menace. He is the loyal friend that will stand up for Dennis no matter what and can be considered his second-in-command. • Kevin "Pie-Face" (voiced by
Gary Martin) is Dennis' other best friend and fellow Menace. He is portrayed as being dim-witted and at times cowardly, as well as being a fan of pies (hence his nickname). •
Walter the Softy (voiced by
Judy Bennett) is Dennis' next-door neighbour, rival and major enemy. He is always exasperated with Dennis' mischief and often tries to come up with ideas to humiliate and outshine him. But he is never successful as his plans tend to backfire. • Matilda (voiced by
Eve Karpf) is Walter's best friend and girlfriend, often seen with him and swooning over him. Matilda will also give Walter cucumber sandwiches with the crust cut off on their picnics. •
Sgt. Slipper (voiced by
Colin McFarlane) is a local policeman and another enemy of Dennis, usually being the first one to deal with Dennis' antics outside his house, and often is seen with the Colonel. He is a bit clumsy at times and often overreacts to things. Seeing as there have been occasions where he and Dennis have encountered a common enemy, however, there have also been times when he proves himself to be extremely responsible, adept (enough to both take on the role of judge and pilot a police aircraft in 'The Trial') and effective at his job. • The
Colonel, Godfrey; voiced by
John Baddeley A neighbour of Dennis' family who lives across the road. He is a stereotypical military veteran who is never seen outside of his military uniform. His house resembles a military bunker and he even has a tank parked in his front garden. Likely, he is still in active (albeit limited) service, as he is occasionally seen conducting meetings at the nearby military base and is sometimes accompanied by a platoon of soldiers to tackle an opponent (usually Dennis). The Colonel often recalls memorable battles in his life and is considered an enemy of sorts by Dennis. However, there are occasions when the both of them join forces against a common enemy, such as in the episode 'The Trial', during which they, along with Sergeant Slipper and the Colonel's cousin Hugo, set off to find Gnasher (after the Colonel had made a false accusation against him). • Foo Foo is Walter's pet poodle and Gnasher's rival. She has been seen in a few episodes with Walter holding her while he's scolding Dennis. She tries to beat Gnasher at his own game but fails. Even though she does not appear as often as her master, Foo Foo is a minor antagonist.
Minor and guests • Mrs. Pie Face, Kevin Pie Face's Mum (voiced by
Jill Lidstone) • Mr. Pie Face, Kevin Pie Face's Dad (voiced by
Gary Martin) • The Postman (voiced by
John Baddeley) Like in the comic, the Postman is mostly harassed by Gnasher whenever he tries to deliver the mail to Dennis' House. • Rasher is Dennis' pet pig that made a cameo in the episode
Dennis and the Beanstalk. • Sidney is Dennis' spider based on the comic book spider Dasher that with his web saved the day. Seen in
Secret Agent Dennis. • Walter's Dad (voiced by
Gary Martin) • School Headmaster (voiced by
Colin McFarlane) • Flossy Muggins (voiced by
Sally Grace) is a wacky inventor who helped Dennis build some ingenious inventions. Seen in
Revenge of the Robot. • Dirk Cool (voiced by
Gary Martin) is a secret agent and a master of disguise. Seen in
Special Agent Dennis. • Vilhemina Slop Bucket (voiced by
Mollie Sugden) is a crazed, villainous
dinner lady who seeks world domination which includes making everyone eat her revolting leftover school dinners. Seen in
Secret Agent Dennis. • Aunt Beryl is Gran's sister. • Hugo (voiced by
Simon Callow) is the Colonel's adventurer cousin who helped Dennis and the others save Gnasher and other Abyssinian tripe hounds from the rat catchers. Seen in
The Trial. • Mr Smiley (voiced by
Derek Nimmo) is a nutty psychiatrist, who tried Dennis like practical jokes on the parents during his course on "How to Understand Children", but couldn't get the better of Dennis even though the parents thought he was worse than him. Seen in
Dennis and the Grown-Ups • Slasher Brown (voiced by
Denis Quilley) is Walter's twisted uncle, who runs the barbershop. Seen in
Hair Today, Gone Tomorrow as the main antagonist. • Reg Trademark (voiced by
John Baddeley) is an eccentric inventor who makes insane and useless gadgets. He builds a shopping mall and uses subliminal messages to make the customers buy his on sale gadgets. Seen in
Malled. • Bertie Blenkinsop is a fellow softy and friend of Walter. Seen in
Snowbound. • Spotty Perkins is a fellow softy and friend of Walter. Seen in
Snowbound. • Captain Trout (voiced by
Billy Connolly) is a sailor who enlists Dennis and the gang as the crew aboard his ship, the S.S. Rustbucket. Despite managing to capture the boys' interest when he relates to them how he lost his father, Captain Prefab to a whale known as Dopey Mick (a parody of
Moby Dick) Captain Trout is essentially a strict, no-nonsense person – which results in Dennis very quickly losing all respect for him when he discovers this! However, he is grateful to the gang for their role in helping him be reunited with his father, and when they help him escape from the whale. Both captains appear in
Dennis Ahoy! Captain Prefab later appears in a non-speaking cameo role in
Summer Holiday. ==Episodes==