There are several characters in the Horrid Henry series.
1. Horrid Henry
- Henry is rather horrid, as one can deduce from his name. He can be disruptive in class, be rude to people, including his parents, and horrid to his boastful and rather spoiled brother, Peter. He actually has a good heart -- caring for his family, and even Peter in some episodes -- but his family, teachers, and certain classmates do not seem to think so. The eleven-year old wears a blue T-shirt with a yellow stripe in between, blue jeans and green sneakers.
- Peter is Henry's younger brother, who studies in the same school as him. He is normally being referred to as "worm" by Henry, and will then whine to his parents that Henry was horrid to him/mean to him/called him names etc.. Despite his name (Perfect), Peter is spoiled and rather self-centered. He seems to be desperate of praise and seeing Henry get into trouble; he would complain to his parents about the most minor things that Henry did, some of which he did not do at all. He sometimes even takes credit for Henry's rare good deeds, like in Horrid Henry's Perfect Day and Horrid Henry, Horrid Headmaster. With immaculate, yellow hair on his head, Peter is normally being seen wearing a red jumper and bluish grey jeans.
- Mum is Henry's and Peter's mother, and she is always healthy, preparing vegetables for dinner, much to Henry's disgust. Peter is the apple of her eye; she believes Peter when he is telling a lie and not Henry despite telling the truth. She wears a purple cardigan with a pinkish shirt under. She has blonde hair and wears glasses. Mum also wears blue jeans and pink ballet shoes.
- The father of the siblings, Dad yells at Henry but rarely at Peter, thinking that Henry is always the one at fault. Like Mum, he never trusts Henry to be well-behaved. His quotes? "Go to your room now, Henry!" or "No pocket money/TV/computer games/sweets for a month!". He tends to show favoritism when it comes to the siblings, obviously favoring Peter than Henry. He is always on Mum's side, rarely letting Henry getting his own way, but sometimes sharing the same point of view. Dad has curly, brown hair and is seen wearing a blue jacket over an orange shirt with brown pants.
- Miss Battle-Axe is a strict school teacher that teaches Henry's class. She seems to have a particular disliking for Henry, which may be because Henry interrupts and disrupts her class. The teacher wears pointy glasses and has gray hair. She also wears a green cardigan, pale chartreuse top, brown skirt, and brownish stockings. Despite hating her class, the strict teacher is quite tough, considering the fact that many teachers had quit after teaching Henry's class, mainly because of him.
- Moody Margaret is a moody girl (obviously) who is always fussing and wanting to get her own way. She is portrayed as a "villain" in the series. Her best friend is Sour Susan and Margaret also lives next door to Horrid Henry. She has magenta hair in a spiky ponytail. Henry and Margaret are enemies. Margaret has a secret club whilst the latter has a Purple Hand fort. She has a talent for screaming and often competes with Henry.
- Aerobic Al: An extremely athletic boy who is one of Henry's closest friends
- Beefy Bert: A big boy who wears a blue shirt, and whose immediate answer to any question is "I dunno"
- Brainy Brian: An intelligent boy in Henry's class
- Bunny: Peter's adorable soft toy
- Ed Banger: The lead singer of Henry's favorite band
- Fang the Hamster: Henry's loyal, vicious hamster
- Fluffy the Cat: The family's cat who often feuds with Fang
- Goody-Goody Gordon: One of Peter's best friends
- Greedy Graham: A greedy boy in Henry's class
- Great Aunt Greta: The great-aunt of Henry whom always call him "Henrietta"
- Lazy Linda: A girl whom is often seen sleeping
- Mrs Cynthia Oddbod: The headmistress of Ashton Primary School
- Miss Lydia Lovely: Peter's teacher whom has a gentle nature
- Rabid Rebecca: The toughest teenager in town who once babysat Henry and Peter
- Rich Aunt Ruby: The wealthy aunt of Henry
- Rude Ralph: Henry's best friend who is rude
- Sour Susan: The best friend of Margaret
- Weepy William: A boy in Henry's class who is always crying
- Nasty Nicola: Henry's girlfriend
- Clever Clare: A girl in Henry's class that is seen clever in the books, but is only seen in the episode where Rude Ralph sings a song about him being rude
- Bob: Known as "Bob Sir" to some, he is the boss of Dad
- Bossy Bill: The son of Bob
- Dizzy Dave: A boy in Henry's class who is always spinning and knocking things over
- Fiery Fiona: A girl who is angry all the time
- Gorgeous Gurinder: A girl in Henry's class who is gorgeous
- Greasy Greta: A lady in charge of the packed lunch room
- Kung-Fu Kate: A girl in Henry's class who is always doing Kung-Fu
- Lisping Lily: New Nick's young sister
- Madame Tutu: The teacher of a dance class
- Moody Margaret's parents: The parents who spoil their daughter Margaret
- Pimply Paul: The husband of Prissy Polly
- Prissy Polly: The wife of Pimply Paul
- Stuck-Up Steve: The cousin of Henry
- Soggy Sid: Henry's swimming teacher and the school's sports coach
- Tell-Tale Tim: One of Peter's friends
- Tidy Ted: One of Peter's friends
- Vomiting Vera: Henry's and Peter's niece, who is always vomiting
- Vicious Vicky: Sour Susan's daughter
- Kind Kelly: Is eating Ice Cream stealing crying Waving playing ballet class My dad playground 40. Brilliant Bella: football game classroom
- The initials of all characters are the same. Examples are:
- Horrid Henry
- Perfect Peter
- Boudicca Battle-Axe
- However, there is one exception: Cynthia Oddbod