Bella is a young immigrant fresh off the boat from Italy who cannot speak, read, or write in English. Desperate to send money home to her starving family, she takes a job at the Triangle shirtwaist factory. Her lack of English makes her vulnerable to manipulation by her landlords and bosses, but she maintains a fervent spirit and a strong capacity to dream of a better life.

Jane is a wealthy but discontented young socialite living in a restrictive environment. She feels stifled by her rigid schedule, heavy clothing, and the strict rules enforced by her governess. Curious about the working-class people she sees from her automobile, she increasingly questions the limitations placed on women of her status and longs to attend college.

Yetta is a fervent Russian Jewish immigrant who fled a violent pogrom to seek safety in America. Working as a shirtwaist maker, she fully dedicates herself to the labor movement and women's suffrage. As an uncompromising activist, she demands systemic change and refuses to settle for partial victories or let romance distract from her political cause.

Rahel is Yetta's older sister, who immigrated to the United States years earlier to escape persecution in Russia. While she actively helps coordinate union efforts, she holds a pragmatic view of social justice that contrasts sharply with Yetta's radicalism. She believes in securing a stable life and values personal happiness alongside her political goals.

Miss Millhouse is Jane Wellington's strict and oppressive governess. She acts as a relentless enforcer of high-society rules, confining Jane to a rigid schedule of socially acceptable activities. She views women primarily as assets to be married off and aggressively guards Jane against lower-class influences.

Signor Carlotti is a foreman at the Triangle shirtwaist factory. He enforces harsh conditions, docking pay for minor mistakes and threatening workers with termination. He uses psychological manipulation to control his employees, occasionally offering small bribes or invoking their families' well-being to prevent them from joining the union.

Pietro is a handsome Italian immigrant who provides his distant cousin, Bella, with a place to live when she arrives in America. He serves as her guide and translator in a city where her native language is often dismissed, though his own life is heavily restricted by his labor boss.

Rocco is the eldest son of the Luciano family, who rent space to Bella. Unlike his parents, who take advantage of Bella's inability to speak English, Rocco acts with genuine kindness. He secretly learns English and serves as an advocate for Bella when she is confused by the city's ways.

Mr. Corrigan is the Wellingtons' Irish immigrant chauffeur and a father of seven children. He treats Jane with more genuine affection than her own family does, offering her a working-class perspective. He supports the labor movement but must carefully balance his sympathies with the need to provide for his family.

Eleanor is a student at Vassar College who introduces Jane to the women's rights movement and the realities of class struggle. While she openly criticizes the social expectations placed on women, she cynically accepts her family's wealth to fund her activism.

Harriet is the five-year-old daughter of the Triangle factory owners. She is an excitable, mischievous child who chafes under the restrictive, upper-class clothing her mother forces her to wear. Her youth makes her open to progressive ideas about the world.

Signora Luciano is Bella's crude-mannered landlady. She relies on the labor of her boarders and children to make ends meet, aggressively pushing Bella to make artificial flowers at night. She works with her husband to exploit Bella's inability to speak English.

Signor Luciano is the patriarch of the family hosting Bella. He takes advantage of Bella's illiteracy by collecting her wages and falsely promising to wire the money to her family in Italy, while secretly keeping the funds for his own household.

Mr. Cohen is a young student in Rahel's English class who runs his own grocery business. He represents a stable, traditional American life, contrasting with the radical labor politics that consume the striking workers.

Jacob is a young fabric cutter at the Triangle factory. Unlike the striking shirtwaist workers, the cutters hold slightly more power and frequently show carelessness on the factory floor. He develops a romantic interest in Yetta, though his history as a strike-breaker creates initial tension.

Charles is a first-year law student who attends classes next door to the Triangle factory. When the striking workers ask him if any laws can help their cause, he takes a genuine interest in researching labor regulations.

Mr. Blanck is the wealthy co-owner of the Triangle shirtwaist factory. He vehemently opposes the workers' strike, hiring private police and denying the existence of a strike to the press. Despite his harsh business practices, he provides a luxurious life for his family.

Mrs. Blanck is the wife of the Triangle factory owner. She openly shares that she and her husband struggled for years before acquiring their wealth. She is eager to provide her daughters with the refinement she lacked.

Millicent is the shy, adolescent daughter of the Triangle factory owners. Raised in luxury, she is largely shielded from the harsh realities of her father's business, though she occasionally overhears his warnings about the factory's dangers.

Pearl is a wealthy young socialite who attends tea parties with Jane. She strictly adheres to high-society norms and dismisses any serious discussion of working-class struggles, finding such topics unmentionable in polite company.

Mr. Wellington is Jane's father, a businessman who has only recently earned his wealth. He is eager to solidify his family's status by marrying Jane into an established family. He strongly opposes women's rights and utilizes strike-breakers in his own business dealings.