Margaret "Meg" March
Meg, the eldest sister, is 16 when the story starts. She is referred to as a beauty, and manages the household when her mother is absent. According to Alcott's description of the character, she is brown-haired and blue-eyed, and has particularly beautiful hands. Meg fulfills expectations for women of the time; from the start, she is already a nearly perfect "little woman" in the eyes of the world. Meg is based in the domestic household; she does not have significant employment or activities outside it. Before her marriage to John Brooke, while still living at home, she often lectures her younger sisters to ensure they grow to embody the title of "little women".
Meg is employed as a governess for the Kings, a wealthy local family. Because of their father's family's social standing, Meg makes her debut into high society, but is lectured by her friend and neighbor, Theodore "Laurie" Laurence, for behaving like a snob. Meg marries John Brooke, the tutor of Laurie. They have twins, Margaret "Daisy" Brooke and John "Demi" Brooke. The sequel, Little Men, mentions a baby daughter, Josephine "Josy" Brooke, who is 14 at the beginning of the final book.
Critics have portrayed Meg as lacking in independence, reliant entirely on her husband, and "isolated in her little cottage with two small children".:204 From this perspective, Meg is seen as the compliant daughter who does not "attain Alcott's ideal womanhood" of equality. According to Sarah Elbert, "democratic domesticity requires maturity, strength, and above all a secure identity that Meg lacks".:204 Others believe that Alcott does not intend to belittle Meg for her ordinary life, and portrays her in loving details, suffused in a sentimental light. 
Josephine "Jo" March
The principal character, Jo, 15 years old at the beginning of the book, is a strong and willful young woman, struggling to subdue her fiery temper and stubborn personality.
The second-oldest of four sisters, Josephine March is the boyish one; her father has referred to her as his "son Jo", and her best friend and neighbor, Theodore "Laurie" Laurence, sometimes calls her "my dear fellow", and she alone calls him Teddy. Jo has a "hot" temper that often leads her into trouble. With the help of her own misguided sense of humor, her sister Beth, and her mother, she works on controlling it. It has been said that a lot of Louisa May Alcott shows through in these characteristics of Jo.
Jo loves literature, both reading and writing. She composes plays for her sisters to perform and writes short stories. She initially rejects the idea of marriage and romance, feeling that it would break up her family and separate her from the sisters whom she adores. While pursuing a literary career in New York City, she meets Friedrich Bhaer, a German professor. On her return home, Jo rejects Laurie's marriage proposal.
After Beth dies, Professor Bhaer woos Jo at her home, when "They decide to share life's burdens just as they shared the load of bundles on their shopping expedition".:210 She is 25 years old when she accepts his proposal. The marriage is deferred until her unexpected inheritance of her Aunt March's home a year later. "The crucial first point is that the choice is hers, its quirkiness another sign of her much-prized individuality.":21 They have two sons, Robin "Rob" Bhaer and Theodore "Teddy" Bhaer. Jo also writes the first part of Little Women during the second portion of the novel. According to Elbert, "her narration signals a successfully completed adolescence".:199
Elizabeth "Beth" March
Beth, 13 when the story starts, is described as kind, gentle, sweet, shy, quiet and musical. She is the shyest March sister.:53 Infused with quiet wisdom, she is the peacemaker of the family and gently scolds her sisters when they argue. As her sisters grow up, they begin to leave home, but Beth has no desire to leave her house or family. She is especially close to Jo: when Beth develops scarlet fever after visiting the Hummels, Jo does most of the nursing and rarely leaves her side. Beth recovers from the acute disease but her health is permanently weakened.
As she grows, Beth begins to realize that her time with her loved ones is coming to an end. Finally, the family accepts that Beth will not live much longer. They make a special room for her, filled with all the things she loves best: her kittens, piano, Father's books, Amy's sketches, and her beloved dolls. She is never idle; she knits and sews things for the children who pass by on their way to and from school. But eventually she puts down her sewing needle, saying it grew "heavy." Beth's final sickness has a strong effect on her sisters, especially Jo, who resolves to live her life with more consideration and care for everyone. The main loss during Little Women is the death of beloved Beth. Her "self-sacrifice" is ultimately the greatest in the novel. She gives up her life knowing that it has had only private, domestic meaning.":206–207
Amy Curtis March
Amy is the youngest sister and baby of the family, aged 12 when the story begins. Interested in art, she is described as a "regular snow-maiden" with curly golden hair and blue eyes, "pale and slender" and "always carrying herself" like a proper young lady. She is the artist of the family. Often "petted" because she is the youngest, Amy can behave in a vain and self-centered way.:5 She has the middle name Curtis, and is the only March sister to use her full name rather than a diminutive.
She is chosen by her aunt and uncle to travel in Europe with them, where she grows and makes a decision about the level of her artistic talent and how to direct her adult life. She encounters "Laurie" Laurence and his grandfather during the extended visit. Amy is the least inclined of the sisters to sacrifice and self-denial. She behaves well in good society, at ease with herself. Critic Martha Saxton observes the author was never fully at ease with Amy's moral development and her success in life seemed relatively accidental. However, Amy's morality does appear to develop throughout her adolescence and early adulthood, and she is able to confidently and justly put Laurie in his place when she believes he is wasting his life on pleasurable activity. Ultimately, Amy is shown to work very hard to gain what she wants in life, and to make the most of her success while she has it.:5
Due to her early selfishness and attachment to material things, Amy has been described as the least likable of the four sisters, but she is also the only one who strives to excel at art purely for self-expression, in contrast to Jo, who sometimes writes for financial gain.
- Margaret "Marmee" March — The girls' mother and head of household while her husband is away. She engages in charitable works and lovingly guides her girls' morals and their characters. She once confesses to Jo that her temper is as volatile as Jo's, but that she has learned to control it.:130 Somewhat modeled after the Author's own mother, she is the focus around which the girls' lives unfold as they grow.:2
- Robin "Father" March — Formerly wealthy, the father is portrayed as having helped friends who could not repay a debt, resulting in his family's genteel poverty. A scholar and a minister, he serves as a chaplain in the Union Army during the Civil War and is wounded in December 1862. After the war he becomes minister to a small congregation.
- Professor Friedrich Bhaer — A middle-aged, "philosophically inclined", and penniless German immigrant in New York City who was a noted professor in Berlin, also known as Fritz. He initially lives in Mrs. Kirke's boarding house and works as a language master.:61 He and Jo become friends, and he critiques her writing. He encourages her to become a serious writer instead of writing "sensation" stories for weekly tabloids. "Bhaer has all the qualities Bronson Alcott lacked: warmth, intimacy, and a tender capacity for expressing his affection—the feminine attributes Alcott admired and hoped men could acquire in a rational, feminist world.":210 They eventually marry, raise his two orphaned nephews, Franz and Emil, and their own sons, Rob and Teddy.
- Robin and Theodore Bhaer ("Rob" and "Teddy") — Jo's and Fritz's sons, introduced in the final pages of the novel, named after the March girls' father and Laurie.
- John Brooke — During his employment as a tutor to Laurie, he falls in love with Meg. He accompanies Mrs. March to Washington D.C. when her husband is ill with pneumonia. When Laurie leaves for college, Brooke continues his employment with Mr. Laurence as a bookkeeper. When Aunt March overhears Meg rejecting John's declaration of love, she threatens Meg with disinheritance because she suspects that Brooke is only interested in Meg's future prospects. Eventually Meg admits her feelings to Brooke, they defy Aunt March (who ends up accepting the marriage), and they are engaged. Brooke serves in the Union Army for a year and is sent home as an invalid when he is wounded. Brooke marries Meg a few years later when the war has ended and she has turned twenty. Brooke was modeled after John Bridge Pratt, her sister Anna's husband.
- Margaret and John Laurence Brooke ("Daisy" and "Demijohn/Demi")— Meg's twin son and daughter. Daisy is named after both Meg and Marmee, while Demi is named for John and the Laurence family.
- Josephine Brooke ("Josy" or "Josie") - Meg's youngest child, named after Jo. She develops a passion for acting as she grows up.
- Uncle and Aunt Carrol — Sister and brother-in-law of Mr. March. They take Amy to Europe with them, where Uncle Carrol frequently tries to be like an English gentleman.
- Florence "Flo" Carrol — Amy's cousin, daughter of Aunt and Uncle Carrol, and companion in Europe.
- May and Mrs. Chester — A well-to-do family with whom the Marches are acquainted. May Chester is a girl about Amy's age, who is rich and jealous of Amy's popularity and talent.
- Miss Crocker — An old and poor spinster who likes to gossip and who has few friends.
- Mr. Dashwood — Publisher and editor of the Weekly Volcano.
- Mr. Davis — The schoolteacher at Amy's school. He punishes Amy for bringing pickled limes to school by striking her palm and making her stand on a platform in front of the class. She is withdrawn from the school by her mother.
- Estelle "Esther" Valnor — A French woman employed as a servant for Aunt March who befriends Amy.
- The Gardiners — Wealthy friends of Meg's. Sallie Gardiner is a well-to-do friend of Meg's who later marries Ned Moffat.
- The Hummels — A poor German family consisting of a widowed mother and six children. Marmee and the girls help them by bringing food, firewood, blankets and other comforts. They help with minor repairs to their small dwelling. Three of the children die of scarlet fever and Beth contracts the disease while caring for them. The eldest daughter, Lottchen "Lotty" Hummel, later works as a matron at Jo's school at Plumfield
- The Kings — A wealthy family with four children for whom Meg works as a governess.
- The Kirkes — Mrs. Kirke is a friend of Mrs. March's who runs a boarding house in New York. She employs Jo as governess to her two daughters, Kitty and Minnie.
- The Lambs — A well-off family with whom the Marches are acquainted.
- James Laurence — Laurie's grandfather and a wealthy neighbor of the Marches. Lonely in his mansion, and often at odds with his high-spirited grandson, he finds comfort in becoming a benefactor to the Marches. He protects the March sisters while their parents are away. He was a friend to Mrs. March's father, and admires their charitable works. He develops a special, tender friendship with Beth, who reminds him of his late granddaughter. He gives Beth the girl's piano.
- Theodore "Laurie" Laurence — A rich young man who lives opposite the Marches, older than Jo but younger than Meg. Laurie is the "boy next door" to the March family, and has an overprotective paternal grandfather, Mr. Laurence. After eloping with an Italian pianist, Laurie's father was disowned by his parents. Both he and Laurie's mother died young, and the boy Laurie was taken in by his grandfather. Preparing to enter Harvard, Laurie is being tutored by John Brooke. He is described as attractive and charming, with black eyes, brown skin, and curly black hair. He later falls in love with Amy and they marry; they have one child, a little girl named after Beth: Elizabeth "Bess" Laurence. Sometimes Jo calls Laurie "Teddy". Though Alcott did not make Laurie as multidimensional as the female characters, she partly based him on Ladislas Wisniewski, a young Polish émigré she had befriended, and Alf Whitman, a friend from Lawrence, Kansas.:202:241:287 According to author and professor Jan Susina, the portrayal of Laurie is as "the fortunate outsider", observing Mrs. March and the March sisters. He agrees with Alcott that Laurie is not strongly developed as a character.
- Elizabeth Laurence ("Bess") - The only daughter of Laurie and Amy, named for Beth. Like her mother, she develops a love for art as she grows up.
- Aunt Josephine March — Mr. March's aunt, a rich widow. Somewhat temperamental and prone to being judgmental, she disapproves of the family's poverty, their charitable work, and their general disregard for the more superficial aspects of society's ways. Her vociferous disapproval of Meg's impending engagement to the impoverished Mr. Brooke becomes the proverbial "last straw" that actually causes Meg to accept his proposal. She appears to be strict and cold, but deep down, she's really quite soft-hearted. She dies near the end of the first book, and Jo and Friedrich turn her estate into a school for boys.
- Annie Moffat — A fashionable and wealthy friend of Meg and Sallie Gardiner.
- Ned Moffat — Annie Moffat's brother, who marries Sallie Gardiner.
- Hannah Mullet — The March family maid and cook, their only servant. She is of Irish descent and very dear to the Family. She is treated more like a member of the family than a servant.
- Miss Norton — A friendly, well-to-do tenant living in Mrs. Kirke's boarding house. She occasionally invites Jo to accompany her to lectures and concerts.
- Susie Perkins — A girl at Amy's school.
- The Scotts — Friends of Meg and John Brooke. John knows Mr. Scott from work.
- Tina — The young daughter of an employee of Mrs. Kirke. Tina loves Mr. Bhaer and treats him like a father.
- The Vaughans — English friends of Laurie's who come to visit him. Kate is the oldest of the Vaughn siblings, and prim and proper Grace is the youngest. The middle siblings, Fred and Frank, are twins; Frank is the younger twin.
- Fred Vaughan — A Harvard friend of Laurie's who, in Europe, courts Amy. Rivalry with the much richer Fred for Amy's love inspires the dissipated Laurie to pull himself together and become more worthy of her. Amy will eventually reject Fred, knowing she does not love him and deciding not to marry out of ambition.
- Frank Vaughan — Fred's twin brother, mentioned a few times in the novel. When Fred and Amy are both travelling in Europe, Fred leaves because he heard his twin is ill.