A large number of characters appear in the Moomin series by Swedish-speaking Finnish writer Tove Jansson. The original Swedish names are given with the etymologies and word associations suggested by Yvonne Bertills in her 2003 dissertation.Yvonne Bertills, Beyond Identification: Proper Names in Children's Literature, 2003, dissertation for Åbo Akademi University

Main characters

Moomintroll

Moomintroll ( – invented mumin + troll, "troll"; also simply Moomin) is the protagonist of most of the books.

In the cartoon strip Moomintroll finds himself beset by endless problems. He is a "moomin" – a little white troll with a hippopotamus-like big round snout.

Moomin is very close with Snorkmaiden. They have a very sweet and romantic relationship in the early books. However, later on he and Snorkmaiden are not seen together as often, and after Moominland Midwinter Moomin refers to Snorkmaiden as a friend.

His best friend is Snufkin. Snufkin is inspired by Atos Wirtanen, Tove Jansson’s close friend and at one point, fiancé. Moomintroll is also an author avatar for Jansson, meaning the two characters were based on real-life lovers. Because of this real-life parallel, their relationship is sometimes examined in the context of queer theory.

Moomintroll was initially called "snork". Jansson described him as her alter ego. The character has a mostly positive reception from critics.

The asteroid 58345 Moomintroll was named in his honor.

Moominmamma

Moominmamma () – the mother of Moomintroll. She is very nurturing and calm. She is almost never without her handbag, which contains essentials like woolly socks, tummy powder, and bark. She makes bark boats every summer, and the first one goes to her favorite.

Moominpappa

Moominpappa () – orphaned in his younger years, he is a somewhat restless soul who left the orphanage to venture out into the world in his youth, but has now settled down. His eagerness to try new things often sets a story in motion. He usually wears a black top-hat. In the 1990s animation Moominpappa writes his memoir.

Snorkmaiden

( – snorkig, "snooty, snotty"; fröken, "Miss") – Moomintroll's fair lady friend and admirer. She does fall in love with others sometimes, but returns to Moomintroll before things get too serious. She has blonde hair and sports a golden anklet. She changes color according to her mood, with her baseline color in the books described as pale yellow. Snorks are almost identical to Moomins except that Snorks come in different colors (Moomins are white), have hair on their heads, and their fur changes color depending on their mood. However in the 1990s animation, she and her brother are always the same color. Snorkmaiden is known as Fraulein in the Japanese dub of the 1990s animated series.

Snufkin

( – dialectical snusmumrik or mumrik, "old man who talks carelessly; old codger, old bore; old snuff-taker; snotty or scruffy old man," derived from snus, "snuff, chewing tobacco" + interjection mum, also in mumla "mumble," with pejorative ending -ik) – Moomintroll's best friend, the son of the elder Mymble and the Joxter, and half-brother to the Mymble's daughter and Little My. Snufkin wears old green clothes and a wide-brimmed hat that he has had since birth. He lives in a tent, smokes a pipe, and plays the harmonica. He is based on Tove Jansson's ex-fiancé Atos Wirtanen who was also known to wander.Anne Laitinen: Muumit ensimmäisenä lehtenä julkaissut Ny Tid palkittiin (Turun Sanomat 7.11.2006)

He lives a nomadic lifestyle, only staying in Moominvalley in the spring and summer, but leaving for warmer climates down south every winter instead of hibernating through the winter as the others of Moominvalley do.

The character has a mostly positive reception from both fans and critics.

Little My

( – my, "micron, mu") is a small, determined, and fiercely independent Mymble. When she wants something done, she does it straight away. She is very aggressive and totally disrespectful, but can be a good friend. She is Snufkin's sister and first appeared in The Exploits of Moominpappa, in which her small stature is explained as resulting from arrest of growth. Little My's age and relation to the Joxter and Snufkin has notable contradiction, mainly between Moominpappa's Memoirs and Moominsummer Madness.

Supporting characters

Alicia

() – Alice, the Witch's granddaughter. Like the Witch, she first appeared in the animated 1990 series and does not appear in the original stories or comic strips. She likes the Moomins and plays with them on the sly whenever the Witch is otherwise occupied. She is a witch-in-training herself, and develops several magic skills during the series, most notably walking on water, underwater-breathing, and running at lightning speed.

The Ancestor

() – the Moomintrolls are descended from small, shaggy trolls living in tiled stoves. One of those is still dwelling in the Moomin family's bathing house cupboard and stove. He is called the Ancestor and makes appearances in Moominland Midwinter and Moominvalley in November.

The Antlion

() – in the Moomins universe, antlions are big, burrowing lion-like animals with slender bodies and big claws. In The Moomins and the Great Flood, Moominmama encounters a territorial antlion that sprays sand in her eyes and then tries to drag her down into his den. In Finn Family Moomintroll, Moomintroll and Snork use the hobgoblins hat to turn the antlion into a hedgehog.

Audrey Glamour

Minor character from the comic Moomin on the Riviera.

Aunt Jane

Aunt Jane (in Finnish Jenni-täti) is the rich and cranky sister of Moominpappa's mother who appeared in the comic Moomin and Family Life. She is also featured in Episode 27 of the animated 1990 series.

Captain Rum-Pot

A pirate who appears in the 1990 series.

Daddy Jones

(, Swedish "King"/ "Self-Ruler"; i.e. "autocrat") – the Autocrat in The Exploits of Moominpappa. He owns a fairground full of surprises, sits on a throne and gives a blast on his foghorn when he makes royal proclamations.

Dame Elaine

A female ghost character living in an old manor house. She only appears in the animated 1990 series.

The Dweller Under the Sink

() – a small furry creature that lives under the sink in Moomin House. He only appears in Moominland Midwinter and becomes known to Moomintroll when he wakes up during the long winter hibernation undertaken by the whole Moominfamily. Moomintroll tries to strike up a conversation with him by complimenting on his rather bushy eyebrows, but only succeeds in upsetting him.

Edward the Booble

( – dronten, "the dodo") – a dragonlike, gigantic monster (the second largest creature in the world – only his brother is larger) who pays for people's funerals if he accidentally treads on them. He is generally bad tempered because of this. He accidentally aids the launch of the Oshun Oxtra (Ocean Orchestra), a boat invented by Moominpappa's childhood friend, Hodgkins, by sitting in a river bed.

Emma

(Swedish) – the rather bitter stage-rat (teaterråtta) in Moominsummer Madness. She helps the Moomin family understand what a theater is and also collaborates with Moominpappa on his play, The Lion's Brides. Before she introduces herself, the family refers to her as Theprop (the prop) after a misunderstanding.

Fillyjonks

( – no semantic meaning, but with the first element compare filibuffare "joker", filidera, "make bad noise", and with the second, fjompa/fjanta/fjolla + -an = "silly/foolish/fussy woman") The first Fillyjonks we hear of are the late theatre director in Moominsummer Madness (Emma the stage-rat is his widow) and the young Fillyjonk who joins the Snork Maiden in the late night jaunt to the wishing well. Later we meet the psychological study of the "Fillyjonk Who Believed In Disasters" (Tales from Moominvalley). Not a single moment of fantasy or joy, only duties and discipline; she is an extremely methodical person tied down with principles and has a deep rooted belief in prestige and tradition. Nevertheless, after a catastrophe, the Fillyjonk can be freed from the trammels of social expectation and can discover the joys of freedom, irrationality and self-expression. Deep inside she has had a wish to live freely as the Moomin family does, without any worries. Fillyjonks resemble humanoid rodents; they are tall and thin, with long muzzles and raccoon-like rings around their eyes.

Fuzzy

( – såsa, "to linger; to loiter" + djur, "animal") – Sniff's mother. Married to Muddler.

Gaffsie

( – gafsa, "chatter; tittle-tattle") – not much is known about Gaffsie, except that she is a friend of Fillyjonk. She appears most prominently in The Book about Moomin, Mymble and Little My as well as in Tales from Moominvalley in the stories "The Fillyjonk who Believed in Disasters" and "The Fir Tree". She is also mentioned in Moominvalley in November.

Grandpa Grumble

( – onkel, "uncle," also used in the meaning "grandfather"; for the second element, see under Miffle) – an old man who appears in Moominvalley in November. He is quite old and somewhat senile. He uses a cane and owns many pairs of glasses that he carries with him in a basket.

The Groke

( – morra "to growl; to grumble", – "[The] Bogey") – cold and ghost-like, anything she touches will freeze. She initially causes fear, everyone thinking that she is coming to freeze them, but in reality she is just very sad and lonely as she is just seeking friendship and warmth, but is declined by everyone and everything. Her most prominent appearances are in Finn Family Moomintroll, Moominland Midwinter and Moominpappa at Sea.

Hattifatteners

( – with the first element compare hatta, "dither"; the second element is related to fnatta (omkring), "flutter around"; få fnatt, "go crazy or get excited over something"; poss. fnatt, "squirrel") – small white ghost-like creatures that resemble worn socks. Hattifatteners are always on the move and travel the sea in large groups (but always in odd numbers), such as boat convoys. They meet every year on a lonely island. Their only goal in life is to reach the horizon. They may communicate using telepathy. The Hattifatteners cannot see very well, but their sense of touch is very strong, and they can feel ground vibrations and electricity. Hattifatteners assemble once a year when they "recharge" in a thunderstorm, when they can cause electrical burns.Jansson T. Finn Family Moomintroll (1948) Hattifatteners grow from seeds, but only if this seed is sown on Midsummer Eve.Jansson T. Moominsummer Madness (1954)

Hemulens

( – hemul, a legal term, "authority or warrant for something (n.), entitled (adj.)", cf. also adjective ohemul "un-hemul"; "improper, unreasonable") (In Swedish "Hemulen" means "the hemul") – Hemulens feature frequently in the books. One of them is an avid stamp collector, and another is an avid skier. In Finn Family Moomintroll, "un-Hemulenish" (ohemul) contains a sense of "unwarranted, unjustified". Other characters frequently find the Hemulens annoying or overwhelming, as they can be somewhat loud, bossy, abrasive and insensitive, but they are well-intentioned and usually have other redeeming qualities.

Hemulens first appear in Comet in Moominland, featuring one who collect insects and another collecting stamps. The stamp collecting hemulen reappears in the beginning of Finn Family Moomintroll in which he is depressed, as he has every stamp on the face of earth and has lost his purpose in life. Later on, he finds a new purpose: to collect plants.

A female Hemulen raised Moominpappa in an orphanage, and later Moominpappa met her aunt, who looked confusingly like her.Jansson T. The Exploits of Moominpappa (1950)

The Hobgoblin