- Accidental Dance Craze: When she demonstrates everything she doesn't like about dancing, the King thinks she's actually dancing.
- Affectionate Nickname: Her parents call her "Sweetheart" and "Poppet".
- Alliterative List: When she tries to make balloon animals, she says she wants "ducks, dogs and a dinosaur".
- Baby Talk: When she tries to be a baby, she mainly babbles, but occasionally says words like "me a go" or "cakey".
- Bad Liar: When she lies, either her tone or the sheer unlikeliness of the lie give her away.
- Bratty Half-Pint: Can be rude, demanding and/or shouty but isn't as bratty as some other examples of the trope.
- Cassandra Truth: In one of the books, she gets the blame for various misdeeds and claims she didn't do them, but nobody believes her. It turns out that a prince her age from next door was the real culprit.
- Catchphrase: She tends to say, "I want", "I don't want", and "Well.." a lot.
- Character Tics:
- Walks with a skip when happy.
- Circles her feet when she lies.
- Companion Cube:
- When she grows a tomato plant, she names it "Tommy" and plays with it like a toy.
- She owns one set of crayons which she never draws with, only plays with.
- Department of Redundancy Department: When she's putting jam on the toast, she claims that she's putting on "some jam and some jam and some jam and jam".
- Does Not Like Shoes: Mostly goes barefoot, and actually does dislike new shoes.
- Does Not Like Spam: Describes tea as being "yucky".
- Dressed to Plunder: Not usually, but she does own a pirate suit.
- Embarrassing Damp Sheets: Apparently, when she wets the bed, she puts a sheet over it.
- Everyone Calls Her "Barkeep": Gets known as "Princess" and "The Princess".
- Fear of Thunder: Used to be afraid of thunder, but outgrew it.
- Filthy Fun: Likes to play in mud.
- Green Around the Gills: While Playing Sick in "I Feel Sick", she paints her face green.
- Hates Baths: Played with. She doesn't like having to bathe if water gets up her nose, but if it doesn't, she actually enjoys herself.
- Height Angst: Wants to be taller in "I Want to Be Tall" after having a few problems due to her shorter height.
- I Do Not Like Green Eggs and Ham: In "I Want Baked Beans", she thought she didn't like baked beans until she had them, then they became her favourite.
- I'm Taking Her Home with Me!: When she finds Taddy, she wants to keep him.
- Inelegant Blubbering: Like many children her age, she sobs loudly whenever she cries.
- Innocently Insensitive: In "I Want to Win", she asks the adults which game they want to "lose at".
- Jar Potty: Pees in a bucket once when she lost her voice.
- Jerk with a Heart of Gold: While she can be ill-mannered, she's not all bad.
- Lethal Chef: Cannot cook and when she tried once, she got a "cake" that was enough to make her cry.
- Large Ham: Can be a bit of a drama queen like a lot of four-year-olds.
- Limited Wardrobe: Always (well, almost always) wears the same white dress and yellow crown. She even has multiple identical dresses and crowns.
- Literal-Minded: Being a little kid, she often takes things literally, such as thinking she had to comb everyone's hair upon being told that she was "in charge of combing".
- Lost Voice Plot: She loses her voice in "I Want My Voice Back" due to straining her throat and pretends it's still gone when she gets it back.
- Never Learned to Read: Cannot read or write yet.
- No Indoor Voice: When she shouts, she can be really loud.
- Not Allowed to Grow Up: Stays four years old, even though her brother aged two years.
- Ow, My Body Part!: Shouts "Ow, my leg!" twice in "I Want My Plaster".
- Playing Sick:
- In "I Feel Sick", she plays sick to get out of doing things.
- In "I Don't Want to Kiss Great-Auntie", she considers playing sick to get out of kissing her great-aunt, but gives up when she hears the cure tastes of sweaty socks.
- Potty Emergency: Has moments of really having to pee in "I Want My Potty" and "I Want My Voice Back".
- Potty Failure: Wets herself at the end of "I Want My Potty", and apparently wets the bed occasionally.
- Put Off Their Food: For a while, she didn't want spaghetti in "I Don't Like Worms" because it reminded her of worms.
- Talking in Your Sleep: Says "meow" in her sleep in "I Don't Know What to Be".
- The Scream: Often screams loudly when she doesn't get her way or is scared.
- Serious Business: Takes what she wants and doesn't want very seriously.
- Shared Family Quirks:
- She has the same sweet tooth as her mother.
- She gave her teddy bear the same name as her great-auntie gave hers and she uses the same voice for Gilbert as her great-aunt does for her Gilbert.
- Sick Episode: Catches a cold in "I Don't Want a Cold".
- Spoiled Brat: While not a complete brat, she has her bratty moments and is quite demanding, saying, "I want" a lot.
- Sweet Tooth: She likes eating cake, jelly and chocolate.Princess: "The more chocolate, the more yummy!"
- Toilet Humour: Her potty is somewhat of a running gag.
- Why Did It Have to Be Snakes?: Is scared of spiders, rats and monsters.
- You No Take Candle: Not usually, but she does say "me a go" instead of "can I have a go?" when she's being a baby.
- Affectionate Nickname: Calls the Princess "sweetheart".
- Comedic Underwear Exposure: Falls down, revealing her underwear, in "I Want to Go to the Fair".
- Everyone Calls Her "Barkeep": Gets called "The Queen" and (by the Princess) "Mum" and "Mummy".
- Guilty Pleasure: Thinks that eating chocolates is a "bad habit".
- Limited Wardrobe: Wears a crown, blue headdress, purple dress, white apron and brown boots.
- Not So Above It All: Is sometimes the voice of reason, but is still a bit of a goof.
- One Episode Fear: Was afraid of heights only in "I Want to Be Queen".
- Shared Family Quirks: Both she and the Princess have a sweet tooth.
- Still Sucks Thumb: Not normally, but she does suck her thumb with the other adults when she was asked to give up chocolate.
- Sweet Tooth: Very fond of pudding and candy.
- Trademark Favourite Food: Chocolate truffles. While she's not completely obsessed with them, she likes them a lot and often eats them.
- Why Did It Have to Be Snakes?: Is afraid of heights in "I Want to Be Queen", but then it goes away.
- Affectionate Nickname: Calls the Princess "poppet".
- Attention Deficit... Ooh, Shiny!: Seems easily distracted by music.
- Bumbling Dad: Downplayed. He can be distractable and/or incompetent but isn't stupid.
- Cloud Cuckoo Lander: Likes playing with toys.
- Everyone Calls Him "Barkeep": Gets called "The King", "Dad", or "Daddy".
- Gasshole: When the Princess complains about her baby cousin pooping his diaper, the Queen claims that the King farts a lot.
- Limited Wardrobe: Mainly wears black shoes, grey pants, a brown coat and a crown.
- Sleepyhead: Downplayed. Takes a lot of naps, but doesn't seem sleepy all the time.
- Still Sucks Thumb: When the entire main adult cast, including him, tries to give up something so that the Princess will give up her pacifier, they all suck their thumbs.
- Everyone Calls Her "Barkeep": Like most of the characters, she goes by "the Maid".
- Hair of Gold, Heart of Gold: Is very kind and has blonde hair.
- Limited Wardrobe: Mainly wears a blue dress with an apron.
- Lovable Coward: Is probably the most easily scared of the adults.
- Maid: She works as the maid to the royal family.
- Neat Freak: Goes hand-in-hand with her job. She even screams when she sees disorder.
- Not So Above It All: The least goofy of the adults, but sometimes does something wacky, such as screaming at the Princess's messy room and believing the monster to be real.
- Only Sane Woman: She's the least wacky character and most logical.
- The Scream: Not as often as the Princess, but she does scream sometimes.
- Still Sucks Thumb: She sucks her thumb with the other adults when she's unhappy with having to give up using makeup (they all volunteered to give something up so the Princess could give up her pacifier).
- Why Did It Have to Be Snakes?: Is scared of rats and monsters.
- Cloud Cuckoo Lander: Plays with toy soldiers and rides a hobby horse, both of which he takes seriously.
- Companion Cube: Acts like his hobby horse Nessie is a real horse.
- Everyone Calls Him "Barkeep": Like all the other servants, he's just "the General" and doesn't go by a proper name.
- Illness Blanket: In "I Don't Want a Cold", he was the only one besides the Chef to be wrapped in a blanket when the Princess thought all the adults were sick.
- Limited Wardrobe: Wears a uniform all the time that he's very proud of.
- Lovable Coward: Seems the most easily scared adult after the Maid.
- Still Sucks Thumb: In "I Want My Dummy", he chooses Nessie as something he will give up to help the Princess give up her dummy. This disappoints him and he sucks his thumb.
- Why Did It Have to Be Snakes?: Runs away in fear at the mention of nits and seems afraid of spiders and crocodiles too.
The AdmiralAnother one of the castle's servants, who mostly just hangs out in the pond with a floatie.
- Busman's Vocabulary: Talks in sailor jargon a lot.
- Cloud Cuckoo Lander: Often brings unrelated sailor stuff into conversations and thinks a tadpole is a shark.
- Does Not Like Shoes: Tends to go barefoot.
- Everyone Calls Him "Barkeep": Like most other characters, his real name isn't revealed.
- Limited Wardrobe: Mainly wears a sailor suit and a big hat.
- Why Did It Have to Be Snakes?: Is afraid of nits, like most of the other adults.
The Prime MinisterA prime minister, who likes to ride a tricycle.
- Cloud Cuckoo Lander: Likes riding trikes and playing in mud.
- Filthy Fun: Likes the mud as much as the Princess.
- Limited Wardrobe: Always wears the same suit.
- Politicians Kiss Babies: He states kissing babies as part of his job and demonstrates it by kissing Gilbert.
- Why Did It Have to Be Snakes?: Seems to be afraid of nits.
The GardenerA man who grows the vegetables and flowers.
- Ambiguously Brown: Has brown skin and is the only character with brown skin. His ethnicity is unknown.
- Everyone Calls Him "Barkeep": Just like the other characters, he's only known by his job.
- Limited Wardrobe: Always wears the same coat, hat, pants and boots.
- Neat Freak: Likes the garden to be orderly and is sad when he finds a hole in the lawn.
- Catchphrase: Often states that nobody can cook as well as him.
- Everyone Calls Him "Barkeep": Just like most of the characters, he isn't called by name, he's just "the chef".
- Illness Blanket: When Princess thinks all the adults are sick, she wraps him and the General in blankets.
- Limited Wardrobe: Wears his chef's uniform all the time.
- Still Sucks Thumb: Sucks his thumb with the other adults when he has to give up his hobby (in his case, listening to music on the radio).
PussA white, ginger-striped tomcat, and the pet of the princess.
- Butt-Monkey: Often gets the worst of it due to the Princess doing things to him that he doesn't like, like dressing him up or trying to make him stay still or the chef calling him bad.
- Catchphrase: Has a certain variety of meows for different situations:
- His one meow that sounds a bit like "Uh-oh" is said when he thinks he's in trouble.
- He has this one indignant meow that sounds like a grunt followed by a strange meow/growl hybrid.
- Cats Are Mean: Can be a bit rude to Scruff, but it's downplayed as he isn't an outright Jerkass.
- Cats Hate Water: Generally dislikes getting wet.
- Cone of Shame: Gets put in a cone after Princess falls on him.
- Green Around the Gills: When he gets seasick he gets a green face.
- Hypochondria: Not usually, but when the Princess caught a cold, he seemed afraid that he'd caught it off her and seemed relieved when the doctor stated that cats "can't catch people colds".
- Jerk with a Heart of Gold: Can be grumpy and rude but means well.
- A Lizard Named "Liz": Is a cat called "Puss". Cats are sometimes called "pussycats".
- Nearly Normal Animal: Sometimes does circus tricks or stands on two feet, but is still a cat.
- Picky Eater: Sometimes, he will refuse certain foods.
- Sleepyhead: Sleeps as often as most cats.
- Vitriolic Best Buds: With Scruff. He finds him annoying, but they're best friends.
ScruffThe Princess's dog.
- Cone of Shame: He once had to wear a cone after injuring his paw.
- In-Series Nickname: Gets called "Scruffy" sometimes.
- Nearly Normal Animal: He sometimes does something humanlike, but he's pretty much a regular dog and is way less inclined to act humanlike than Puss.
- Potty Emergency: He has to pee during "I Don't Want Help".
- Vitriolic Best Buds: He and Puss have a sort of friendly rivalry.
- Why Did It Have to Be Snakes?: Is afraid of spiders.
Great-AuntieThe Princess's great-aunt, who's very jolly and possesses a teddy bear who's possibly Gilbert's namesake.
- Cool Old Lady: Likes to play games and drink tea.
- Genki Girl: Elderly, but spry.
- No Name Given: Not even a job descriptor is used for her.
- Shared Family Quirks: She and the princess both own teddy bears, which they named "Gilbert", who they speak for in a raspy voice.
MiceA couple of cheeky mice that are sometimes seen in the castle.
- Blowing a Raspberry: One blows a raspberry at Puss.
- Eek, a Mouse!!: Sometimes, they frighten the Princess, the Maid or Puss.
- Nearly Normal Animal: They are mostly like regular mice, but sometimes do humanlike taunts.
- No Name Given: Being wild mice, they likely don't have names.
The BabyThe Little Princess's cousin.
- Baby Talk: Can say a few words but is too young to talk properly.
- The Diaper Change: Gets his diaper changed several times.
- Does Not Like Shoes: Mainly has bare feet.
- Gasshole: Farts a lot.
- Inelegant Blubbering: Cries the way most babies do.
- No Name Given: His name is never revealed.
The DoctorA Scottish-accented doctor who pays house calls. She can be quite abrupt.
- Hypocrite: A poster in her office says, "Beware of spots" but she has freckles all over her body.
- The Medic: Is a professional medical doctor.
- No Name Given: We never find out her name, because she's never addressed.
- Tastes Like Feet: To get the Princess out of Playing Sick, she claims the cure is medicine that "tastes of sweaty old socks".
- Tough Love: She delivers her prescriptions very bluntly, such as "She must go to bed and she must stay there!" in "I Don't Want a Cold" and "No fair for you!" in "I Want to Go to the Fair".
- You No Take Candle: She mostly talks normally, but at one point she slipped into primitive grammar when talking about the prospect of sewing Gilbert's leg back on.Doctor: "Needle, thread."
Princess's AuntThe Princess's aunt and the baby cousin's mother.
- Unnamed Parent: Her name is unrevealed and she's the cousin's mother.
The Little PrinceThe Princess's little brother who was born in the book "I Want a Sister". He has not appeared in the TV series as of yet.
- Everyone Calls Him "Barkeep": Like most of his family, his name isn't revealed.
- Soap Opera Rapid Aging Syndrome: Is about two, even though the Princess has not aged.
AlgernonThe maid's three-year-old nephew.
- In-Series Nickname: "Algie".
Other ChildrenVarious other children have appeared in the books, including a prince who lives next door and three kids who attend the Princess's preschool named Molly, Polly and Willy.
- Everyone Calls Him "Barkeep": One of them is called the Little Duchess.
- Theme Naming: Two girls are called Molly and Polly.
WalterThe Princess's great-uncle, who has a wheelchair.
HoraceThe Princess's pony.
- Odd Name Out: Is the only pet to have a proper name, and the only one to have a two-syllable name.