Catherine is a seventeen-year-old from a modest clergyman's family in the rural village of Fullerton. Initially lacking the typical accomplishments and beauty of a romantic heroine, she possesses a vivid imagination fueled by reading macabre gothic novels. Invited to the resort town of Bath by family friends, she steps into high society with extreme naivety and a literal-minded approach to conversations.

Isabella is a beautiful, fashion-conscious young woman who forms an immediate, intense attachment to Catherine in Bath. Four years older than Catherine, she presents herself as a worldly and devoted companion who shares a love for dramatic gothic fiction. Despite claiming to dislike male attention, she constantly monitors the room for admirers and behaves with noticeable hypocrisy.

Henry is a clever, twenty-five-year-old clergyman from a wealthy and respectable family in Gloucestershire. He possesses a quick wit and a fondness for sarcasm, playfully mocking the social conventions of Bath and the tropes of popular novels. Unlike many men in his society, he openly admits to enjoying gothic fiction and treats Catherine with a mixture of amusement and genuine kindness.

General Tilney is the wealthy, controlling patriarch of the Tilney family and the owner of Northanger Abbey. He is highly invested in status, punctuality, and the material upkeep of his modernized estate. He shows surprising, aggressive hospitality toward Catherine, eagerly inviting her to his home while maintaining a strict, almost tyrannical authority over his own adult children.

Eleanor is Henry's sister and the only daughter of General Tilney. She is an intelligent, sincere young woman who often finds herself isolated at her family's estate when her father and brothers travel. She forms a genuine bond with Catherine, offering a clean contrast to the superficial friendships found in Bath society.

James is Catherine's older brother, currently studying at Oxford. He is a straightforward and trusting young man who quickly becomes enamored with Isabella Thorpe. He relies on his family's modest but respectable income and operates without the guile or ambition of his Bath acquaintances.

John is Isabella's brother and James Morland's friend from Oxford. He is a boastful, loud young man who aggressively pursues Catherine's attention despite her obvious disinterest. He talks endlessly about his horses, his carriage, and the supposed wealth of his acquaintances, showing little regard for the truth or the comfort of others.

Mrs. Allen is a wealthy, childless woman from Fullerton who invites Catherine to accompany her to Bath. She is entirely consumed by fashion, fabrics, and the appearance of those around her. As a chaperone, she is highly ineffective, offering Catherine no practical guidance or protection in the complex social environment of the resort town.

Mr. Allen is a sensible and wealthy gentleman who visits Bath for his health. While he is far more rational than his wife, he remains largely detached from Catherine's daily social interactions, only occasionally stepping in to offer sound advice regarding societal propriety.

Captain Frederick Tilney is Henry's older brother and the heir to the Tilney estate. He is a dashing military man who enjoys flirting with engaged or unavailable women. His manners are noticeably poorer than his brother's, as he takes pleasure in social disruption without regard for the consequences.

Mrs. Thorpe is a widow with six children who spends her time in Bath trying to secure favorable marriages for them. She continuously boasts about her children's minor accomplishments to combat her lack of wealth and fine clothing.

Mrs. Morland is Catherine's practical, sensible mother. As the wife of a country clergyman with ten children, she relies on plain common sense and lacks the dramatic flair of the mothers found in her daughter's favorite novels.

Mr. Morland is a respectable, moderately comfortable clergyman in the village of Fullerton. He is a steady, unpretentious man who provides a stable but unglamorous life for his large family, standing in sharp contrast to the wealthy patriarchs of Bath.