An elderly and loyal Irish steward who has served the Rackrent family for generations. Thady is characterized by his old-fashioned ways, wearing a long greatcoat year-round, and his deep emotional attachment to the aristocratic family. He prefers the comfort of his pipe and the glory of the past to the pragmatic realities of the present, narrating the family's decline with affection and partiality.

The original patriarch of the estate who anglicized his name from O'Shaughlin to retain his lands under British law. A legendary figure of immense hospitality and indulgence, he is famed for inventing raspberry whiskey and throwing lavish parties that leave no guest standing. His extravagant lifestyle sets a standard of decadence for his successors.

The heir to Sir Patrick, sharply contrasting with his father's legendary hospitality. Dour, frugal, and obsessed with the law, he refuses to entertain guests and spends the family's money on endless litigation. He proudly boasts of having a lawsuit for every letter of the alphabet.

A dashing young officer who serves as the epitome of the absentee Anglo-Irish landlord. Spending most of his time gambling in Bath, he leaves the estate in the hands of middlemen who ruthlessly extract high rents from the impoverished tenants to fund his extravagant lifestyle.

The final heir to Castle Rackrent, educated as a lawyer in Dublin but completely inept at estate management. Mild-tempered, passive, and generous to a fault, he avoids his mounting debts by retreating to his bed and seeking comfort in whiskey. He relies heavily on others to make decisions for him.

Thady's ambitious, pragmatic, and highly capable son. Educated as a clerk and an attorney, he rises above his father's servile station to become the powerful agent of Castle Rackrent. He is rational and calculating, sharply contrasting the emotional incompetence of the aristocratic family he works for.

A widow with severe, quasi-Calvinist habits who perfectly matches her new husband's miserly tendencies. True to her maiden name, she operates as a strict economist, forcing servants to observe fasts to save money and exploiting the free labor of children at her charity school.

An unnamed, wealthy heiress whom Sir Kit marries entirely for her fortune and diamonds. She arrives in Ireland as a foreigner facing deep prejudice, struggling to understand the local customs and language. She quickly proves to have a strong will when her husband attempts to seize her personal wealth.

The theatrical and strong-willed youngest daughter of Captain Moneygawl. She marries Sir Condy for the drama of a love match, wearing veils and quoting plays. Her taste for luxury, fine coaches, and private theaters quickly exacerbates the Rackrent family's financial ruin.

A pragmatic local woman and relative of the Quirk family. Though she initially captures Sir Condy's affections, she demonstrates an unsentimental approach to her own survival. She recognizes the value of tangible property and power over empty aristocratic titles.

The rational, English-aligned voice that frames Thady's narrative. He presents himself as an empirical historian documenting the curious customs of the Irish aristocracy, providing glossaries and notes to translate Thady's emotional storytelling for an English audience.

A neighboring gentleman and father to Isabella. He strongly opposes his daughter's romantic entanglement with the indebted Rackrent family, threatening to cut her off from his fortune if she pursues the match.