Silas is a wealthy, self-made businessman who built a massive fortune selling high-quality mineral paint discovered on his family's rural Vermont farm. He holds a fierce pride in his commercial success but feels intensely out of place among Boston's established elite class. He possesses a tireless work ethic but struggles with deep social anxiety, often resorting to clumsy attempts to force his family into high society circles.

Persis is Silas's wife and a former schoolteacher who married him during their modest early years. She operates as her husband's moral compass, frequently reminding him of past misdeeds and cautioning him against extravagant displays of wealth. Though she enjoys their financial security, she misses the simplicity of their earlier life and resents the corrupting influence of high-society ambitions.

Penelope is the older of the two Lapham daughters. She cares very little for the rigid social etiquette of Boston high society, choosing instead to read contemporary literature and offer dry, observant commentary on her family's social climbing. She relies on her sharp wit and intelligence to distance herself from the aristocratic circles her father so desperately desires to enter.

Tom is an energetic young man from an established, old-money Boston family. Unlike his leisure-oriented father, he possesses a strong desire to build his own career, eventually seeking a position in Silas's mineral paint business to utilize his foreign language skills. He carries the polite, refined manners of his aristocratic class, though he pushes back against his family's snobbish expectations regarding his professional and social choices.

Irene is Silas and Persis's younger, highly social daughter. She is conventionally beautiful and invests heavily in mastering the manners, aesthetics, and fashions of Boston's elite class. She actively attempts to conform to upper-class expectations, hoping to secure a prominent place in society and an advantageous marriage.

Bromfield is Tom's father, an aristocratic man who lives comfortably off a dwindling inherited fortune. In his youth, he studied portrait painting in Rome but ultimately abandoned his artistic pursuits for a life of quiet leisure, viewing work as unnecessary for a man of his standing. He treats the working class, including the Laphams, with a mixture of anthropological amusement and mild disdain.

Mrs. Corey is a staunch defender of Boston's strict social hierarchy and old-money traditions. She is fiercely protective of her family's reputation and views the newly wealthy Lapham family as coarse and inappropriate associates for her son. She frequently attempts to steer Tom away from the mineral paint business to preserve the family's dignity.

Rogers is a businessman who provided the initial capital to help Silas launch the mineral paint enterprise years ago. Silas later forced him out of the partnership just before the business became massively lucrative. He returns to Boston seeking investment for new, highly speculative land schemes, heavily leveraging Silas's lingering guilt.

Bartley is a local journalist working on a series called "Solid Men of Boston." He writes about Silas's rise to wealth with a wry, cutting tone that secretly mocks the businessman's lack of sophistication, though he politely accepts Silas's hospitality and gifts in person.

Zerrilla is a strikingly attractive young woman who works as a typist in Silas's mineral paint office. Her physical appearance and her unusually close, secretive dynamic with her employer generate rampant speculation and gossip among the other clerks regarding the true nature of her position.

Walker is the head bookkeeper at Silas's mineral paint company. He is highly observant of the daily office routines and occasionally shares workplace gossip with newer employees, keeping a particularly close eye on Silas's financial and personal behaviors.

Nanny is one of Tom's sisters. She is a scholarly, bookish young woman who is highly critical of modern sentimental literature, preferring more realistic artistic depictions. She aligns closely with her mother's views on maintaining proper social boundaries.

Lilly is Tom's sister. She possesses an artistic temperament and, like the rest of her immediate family, worries greatly about maintaining their elevated social status in the face of Tom's new working-class associations.

Minister Sewell is a prominent local clergyman whose opinions carry significant weight among the Boston elite. He is a pragmatic thinker who openly criticizes the unrealistic emotional expectations set by sentimental romance novels, advocating for realism and common sense in daily life.

Often referred to as "Uncle Jim," James Bellingham is Tom's relative. He is a practical, level-headed man who occasionally assists his nephew with financial investigations and offers measured business advice during commercial crises.

Seymour is the architect hired by Silas to construct a lavish home on Beacon Hill. He tactfully refines his client's garish ideas while consistently encouraging Silas to spend heavily on fashionable additions to match the prestigious neighborhood.

Jim Millon is a deceased soldier who served alongside Silas during the American Civil War. He bravely jumped in front of a bullet, saving Silas's life at the cost of his own, leaving behind a family that Silas feels eternally indebted to.

Molly is the widow of Jim Millon. She struggles deeply with poverty and alcohol, occasionally confronting Silas at his office to demand financial support based on her late husband's sacrifice.

Dewey is a sailor who sporadically returns home from sea to consume his family's funds. His unpredictable presence and drinking habits cause significant stress for his wife, complicating her financial and legal standing.