Jurgis is a strong, young Lithuanian immigrant with thick black hair and an optimistic demeanor. He emigrates to America with his extended family, drawn by the promise of steady work in Chicago's meatpacking district. Energetic by nature, he initially trusts that his physical strength and determination will allow him to provide for his family in their new environment.

Ona is a petite, sweet, and affectionate Lithuanian girl who emigrates to America at a young age. Raised as the daughter of a relatively secure farmer, she is physically delicate but possesses a gentle morality that influences those around her. Her small stature and modest upbringing make the demanding realities of her new workplace exceptionally difficult to endure.

Marija is Ona's cousin, characterized by her broad Slavic face, prominent red cheeks, and powerful physical build. Orphaned young and used to hard labor, she is outspoken, stubborn, and fiercely loyal to her relatives. She eagerly takes a job painting cans to help support the household and shares in the family's dreams of establishing a secure life in Chicago.

Teta Elzbieta is Ona’s stepmother and the mother of six young children. Having enjoyed some status in Lithuania, she tries to maintain her family's traditional customs and cultural dignity in America. She is a long-suffering and resilient woman whose instinct to persevere keeps the large extended family together under challenging circumstances.

Mike Scully is a wealthy, calculating political boss with rat-like eyes who dominates Chicago's meatpacking district. Outwardly presenting himself as a friend to the working class, he secretly collaborates with meatpacking barons to maintain control, fix elections, and protect corporate interests.

Phil Connor is a coarse, red-faced foreman with significant influence in Packingtown due to his connections with the local political machine. He abuses his supervisory power to harass female workers, leveraging their desperate need for income to force their compliance.

Dede Antanas is Jurgis’s sixty-year-old father, a gentle-natured and hardworking man with a fondness for learning. Despite leaving behind his modest farmstead, he remains hopeful about the family's prospects in Chicago. His age makes finding employment difficult, eventually forcing him into a toxic position mopping the floors of the packinghouse pickle rooms.

Jonas is Teta Elzbieta's brother, a physically slight man who formerly worked on his brother-in-law's farm in Lithuania. He convinces the family to move to Chicago after hearing rumors of wealth in America. He takes a physically demanding job pushing trucks at a meatpacking plant to contribute to the family's shared household.

Antanas is the young son of Jurgis and Ona, named after his grandfather. He is a healthy, cheerful child with dark, curly hair and bright black eyes. His arrival brings joy to his parents, motivating Jurgis to endure the worsening conditions around them.

Stanislovas is a thirteen-year-old boy who is small for his age. Economic pressure forces the family to pull him out of school and secure a certificate falsifying his age so he can work filling lard cans. He develops an intense fear of the cold due to his brutal winter commutes.

Kotrina is Teta Elzbieta's eleven-year-old daughter. She takes on significant housekeeping responsibilities for the large extended family while the adults and her older brother go to work in the packing plants, eventually being pushed into selling papers on the street.

Vilimas is one of Teta Elzbieta's young sons. Along with his brother Nikalojus, he is put to work selling newspapers on the streets of Chicago when the family's financial situation becomes strained.

Nikalojus is a ten-year-old boy, another of Teta Elzbieta's sons. He joins his brother Vilimas in the newspaper trade, enduring the difficult and often hazardous environment of downtown Chicago.

Juozapas is one of Teta Elzbieta's younger sons who lost a leg in an accident. Because of his disability, he stays near the home and occasionally searches for food in the local dump to help feed his family.

Kristoforas is Teta Elzbieta's youngest and favorite son. He suffers from a congenital hip deformity and rickets, making him physically vulnerable to the unsanitary living conditions in Packingtown.

Judge Pat Callahan is a corrupt magistrate firmly entrenched in the local political and corporate machine. He dispenses harsh, unyielding judgments against working-class defendants while shielding those connected to organized crime or the meatpacking owners.

Buck Halloran is a local political fixer who facilitates corrupt election practices. He serves as an intermediary between the wealthy elite and the street-level operatives who carry out the machine's bidding.

Bush Harper is a night watchman at a meatpacking plant who moonlights as a political operative for Mike Scully. He recruits immigrant workers, securing their citizenship in exchange for their votes in local elections.

Aniele Jukniene is an elderly widow and washerwoman who operates a cramped, unsanitary lodging house in the Lithuanian district of Chicago. She provides a harsh but necessary first refuge for the family when they enter the city.

Grandmother Majauszkiene is a seasoned Lithuanian neighbor who understands the brutal realities of the Packingtown real estate market. She straightforwardly informs the family about the hidden interest and fees in their housing contract, shattering their financial optimism.

Jokubas Szedvilas is a hearty, overweight Lithuanian immigrant who runs a delicatessen in Packingtown. Though not as prosperous as Jonas believed, he acts as a guide for the newly arrived family, helping them find temporary lodging and warning them about predatory housing contracts.

Tamoszius Kuszleika is an excitable, diminutive man who folds hides at a meatpacking plant by day and earns extra money playing the violin by night. He falls deeply in love with Marija, and his musical talents provide a rare source of joy and entertainment for the immigrant community.

Ostrinski is a wizened, slightly lame Polish immigrant who works as a pants finisher. Because he speaks Lithuanian, he acts as a political mentor to Jurgis, teaching him the foundational concepts of labor organization and working-class solidarity.

Tommy Hinds is a squat, broad-shouldered Union veteran and hotel proprietor. Possessing inexhaustible energy, he uses his business to foster political discussion, openly encouraging his staff and patrons to consider alternative economic systems.

Nicholas Schliemann is a tall, gaunt Swedish philosophy professor who supports himself through seasonal harvest work. He holds radical views on nutrition, the wastefulness of corporate monopolies, and the future of human labor, actively challenging traditional institutions.

Lucas is a former itinerant preacher who views political and economic reform through a religious lens. He maintains that true spiritual teachings are fundamentally aligned with the equitable distribution of resources, rejecting the corruption he sees in formal religious institutions.

Jack Duane is a dapper, cheerful electrical engineer turned petty criminal. After a corporation cheated him out of a patent, he abandoned lawful work to become a safebreaker. He takes a friendly interest in Jurgis, introducing him to the realities of Chicago's underground networks.

Freddie is the handsome, eighteen-year-old son of a prominent meatpacking magnate. Sheltered and careless with his immense wealth, his opulent lifestyle stands in sharp contrast to the extreme poverty experienced by the laborers who generate his family's fortune.