As the story opens, the four March sisters--Meg, Jo, Beth, and Amy--are living in genteel poverty as their father is off serving as a chaplain during the Civil War. Motivated by generosity, they share their Christmas breakfast with a poor family, the Hummels. Soon, they attend a ball and meet their neighbor, Laurie (short for Theodore Lawrence), and befriend the lonely boy. He lives next door with his kind grandfather. Their father is wounded, and Marmee, as they call their mother, visits him with money provided by Jo, who sells her beautiful long hair to pay for the trip.
While Marmee is away, Beth, the sister Jo is closest to, falls ill with scarlet fever, though she recovers by the time Marmee returns. Their father also returns home. John Brooke, who tutors Laurie, falls in love with Meg. While Jo opposes their relationship at first, fearing that it will break up the cozy family circle, she eventually relents when Meg and John get married.
The family's aunt, Aunt Carrol, decides to invite the pretty Amy to Europe, saddening Jo. Jo, who dreams of being a writer, heads to New York City to work as a governess, and meets the charming but absent-minded Professor Bhaer, a man from Germany who encourages her writing. Laurie proposes to Jo, but she refuses to marry him, citing her devotion to her writing. Brokenhearted, Laurie spends time in Europe with Amy. Jo devotes herself to caring for Beth, who dies. As a result, Jo is depressed, though she amuses herself with Meg's twins.
Eventually, Amy and Laurie return from Europe, married, and Professor Bhaer stops by Jo's house and proposes marriage, which she accepts. When Aunt March dies, Jo decides to use her house to open a school that she will run with her husband.
First, the four March sisters meet their neighbor, Laurie. They all become friends with him. Jo is especially close to Laurie. Beth becomes very ill, but she recovers. When the Civil War ends, Mr. March, their father, returns home.
Meg falls in love with Laurie's tutor, John Brooke. They eventually marry. Laurie confesses his love for Jo, but she does not share his feelings. They part ways.
Jo moves to New York City to work as a governess. While she is there, she meets Professor Bhaer and they become friends. Amy travels to Europe. Laurie also travels to Europe, and the two meet there. They fall in love.
They all receive word that Beth has died. Everyone rushes home to be with Marmee and their father. In the end, Professor Bhaer and Jo fall in love and get married. Laurie and Amy also marry.