The images are from the official Emma anime website. Click the head shots for a full-body image of the character.
Emma
The protagonist, a kind and mild-mannered maid. She falls in love with William at first sight. At the start of the series she is employed by Kelly Stowner, who taught her to read and write despite her class. She then goes to work for a country family of German immigrants.
Emma is usually a passive young woman. She does her work quietly and listens to William's enthusiastic conversation without much comment, only speaking up when he tries to do more than she thinks she deserves; it takes a while for her to open up to him.
On the other hand, Emma has been known to stand up for herself. As a child, she was kidnapped to be sold to a London brothel, but escaped; she then supported herself through odd jobs and flower sales until Kelly found her. One gets the idea that the main reason she hasn't run into William's arms and just stayed there is that she isn't sure it's what's best for him.
William
The eldest son of the "new money" Jones family, William is a bright and inquisitive young man with an indecisive streak. On visiting his old governess, Kelly Stowner, he meets Emma and falls for her instantly.
William is a very modern man; he's always buying new gadgets and learning about the latest scientific discoveries, which he enthusiastically explains to Emma. (Their first and only date involved visiting the Crystal Palace, a showcase of scientific and Industrial Revolution advances.) He's also dubious about the sanctity of the class system.
On the other hand, William doesn't have the resolve to do whatever it takes in support of his beliefs. He makes a few attempts to stand up to his father's disapproval of Emma, but always backs off at the threat that it'll break up the family. He throws himself wholly into fitting in, then goes back to his halfhearted defiance. It'll take support from some other strong figures with similar beliefs (like Kelly Stowner) to push him into unhesitatingly pursuing Emma.
Kelly Stowner
Emma's employer and William's childhood governess. A very enlightened woman, she decided to teach Emma to read and write as an experiment in the power of education, and was very pleased with the results. Kelly is practical and can be stern (William took a while to get comfortable dealing with her adult-to-adult), but is very supportive of William and Emma's relationship, doing things like giving Emma a n unheard-of day off for their date.
Prince Hakim Atawari
William's best friend (they were classmates at Eton), a prince from India. He rides in for a visit with a parade of elephants and sets about shaking up the Jones family's lives. Unencumbered by the restrictions of class and society that bind William, he at first flirts with Emma, but backs off for William's sake. He's often impatient with his friend for hesitating about love, and is prone to doing impulsive things like buying a car (without finding out that cars need petrol).
Hakim's Girls
A quartet of Indian dancing girls who accompany Hakim wherever he goes. The four of them act as one. They all wear the same stoic expression and never speak, so it's impossible to distinguish any of them as individuals. "It's just 'cause I like this kind of stuff," admits Kaoru Mori. (Add "scantily clad Indian chicks" to the list, then, along with "shy maids" and "bunny-girls".)
Eleanor Campbell
The young daughter of an "old money" family who falls in love with William. Her father wants them to get married for the Jones' money; his father wants them to get married for the Campbells' status; Eleanor just wants to be with William. She's a sweet and innocent girl, shy about coming out into society but sincere about her first love, so you can't be mad at her for causing William the trouble she does. (He tries to be kind to her, but his thoughts are only with Emma.)
Al
A longtime friend of Kelly Stowner's; Al, Kelly, and Kelly's husband had been an inseperable trio since even before the marriage. Kelly uses this as an excuse to make Al do odd jobs and repairs for her, which he routinely grumbles about but faithfully fulfills. He knows Emma's history and is always ready to lend a hand as far as he can.
Grace Jones
William's oldest younger sister. She's a graceful and classy young woman. Calmer and more mature than her siblings, she often acts like a mother figure, especially when it comes to calming Colin.
Arthur Jones
William's younger brother, about to graduate from Eton. He's practical and somewhat grumpy, and objects very sternly to William's relationship with Emma.
Vivian Jones
William's youngest sister, an outspoken girl who loves shopping, is fascinated with Hakim, and is prone to snap judgments. She pegs Emma as an uncouth gold-digger and vehemently objects to her.
Colin Jones
William's youngest brother, a timid and shy kid. He always seems on the verge of bursting into tears, and the slightest jar can make him start to whimper.
Richard Jones
William's solid and stern father. He is very conscious of his place in the class system - rich, yes, but it's "new money" (earned through business success) rather than "old money" (inherited from aristocrat ancestors). While he wants to overcome this distinction by having William "marry up", he has no tolerance whatsoever for the idea of Emma "marrying up" into his family. This despite some uncomfortable facts about his own history . . .
Stevens
The Jones family butler. He keeps the house in order, makes social arrangements, and covers for William when ordered to, all while keeping a straight face and without giving anyone any idea of what he's thinking. In short, he's a very good butler. (Maybe he's related to Father Renaldo?)
Countess Monica Mildrake
Eleanor's assertive and impulsive older sister. She's very masculine: she rides, and not sidesaddle, either; she walks around in a top hat and carries a cane; and she doesn't pay much attention to her husband. (She doesn't love him; but he worships her, which is why she married him.) Fiercely protective of her sister, almost to the point of a complex. Very direct; doesn't beat around the bush.
Mrs. Trollope
Born Aurelia Hartwick, she's now known as Mrs. Trollope, from the word "misanthrope". She likes some people, though - particularly her friend Dorothea. Unconcerned with appearances, she has short-cropped hair and doesn't pay much attention to society, leaving much of it to write her off as, well, a misanthrope. She lives in the country, as her lungs are too weak for the stress of city society life.
Viscount Campbell
Eleanor's father. Short-tempered, unfaithful, snobbish, classist, and generally not a nice guy. He comes across as a normal, if somewhat stiff and abrupt, nobleman when in company; but he's not above plotting murder to solve his problems.
(Minor Characters)
Robert
A friend of William's. Has encouraged him to be more social. Owns boats. That's all we know.
The Inseperable Trio
From left to right: Alice, Fanny, and Eliza. Three social young women with almost identical tastes; whatever one says, the others will usually repeat agreeably and without irony. Of particular note is that they share a borderline infatuation with Grace Jones. (Their ideal husband would be Grace if she were a male with a title.)
Grace's suitor
We barely see him, but he's a nice, sympathetic guy. In the end it is revealed that she hasn't told her father about him.
Sara & a friend
Sara is the girl at the Leyton shop, where cards and other trinkets are bought. She's dating this guy. What's his name again?
Martha
Mrs. Trollope's childhood maid, called to help her again when she moved to the country. Far more conscious of social norms than her mistress.
Violet Grey
A very expensive prostitute, seen most often in the company of Viscount Campbell. Probably up to no good.
Mrs. Campbell
Eleanor's mom. Seems nice enough.
(At Möders House)
Tasha
The maid who first meets Emma; although they're about the same height and weight, they're different as night and day. Unlike the quiet and organized Emma, Tasha is outgoing, talkative, enthusiastic, impulsive, and somewhat scattered. The two have become roommates, and Tasha enjoys having someone to talk to.
Mrs. Vick and Mr. Bruch
She's the manager of the household, and the one who makes the decision to try out Emma. He seems to be her male counterpart; he makes announcements to the household.
Miss Adèle
The head maid, and Emma's direct superior. Her stern expression goes perfectly with her strict and no-nonsense control of the busy and understaffed household. Although not one to be free with her praise, she approves of how quickly Emma learns, and can be sympathetic if she thinks it's deserved.
Maria
Not much is known about her except that she's more relaxed than her roommate Adèle, and is respected enough that they can converse freely in private.
Johanna
The head cook. Likes Emma, as she's also likes to talk and Emma is a good listener. (She only speaks German, and doesn't realized that Emma can't understand a word of it.)
Ada and Rita
Two cooks. Ada doesn't complain, but fun-loving Rita isn't shy about it.
Hans
A serious, matter-of-fact servant; something of a sourpuss. Other than the always-quiet Emma, he's the only member of the household who doesn't jump at the chance for a party. Seems to be developing the instinct to protect Emma.
Thomas and John
Two servants. At a servants' party, Thomas threw up over clothes lent to him by Hans, and John wrecked a chair in Hans' room. This helps explain why Hans doesn't like parties. Thomas' little brother wants to be a socialist in Berlin.
Alma
A maid, and a major party girl. Will get extremely drunk when she has the chance. Assertive; she pushes around the other maids easily, though not maliciously. Occasionally tries to get Hans to lighten up. Needless to say, she has never succeeded.
Polly
A cheerful and mischievous maid, usually found with Alma.
The Möders
Dorothea
The mother. A sensual woman who enjoys the unusual and dramatic (also, hot baths).
Wilhelm
The father. Made his fortune in the boom brought by the Industrial Revolution.
Ilse
The daughter. A shy little girl. Enjoys stuffed animals.
Erich and Theo
The son, and his pet squirrel. An enthusiastic little boy. Wants to be a gentleman.