The narrative centers on the moral trials of Harriet Byron and the intervention of the virtuous Sir Charles Grandison following a harrowing abduction. Harriet Byron, a young woman of high moral standing, finds herself the target of a predatory suitor, Sir Hargrave Pollexfen, whose actions force her into a precarious social and physical position. Sir Charles Grandison, a paragon of aristocratic virtue and integrity, emerges as her protector, initiating a complex social entanglement that tests the boundaries of duty, honor, and romantic inclination. The story unfolds through an extensive series of letters, providing a multi-perspective view of the characters' internal motivations and the rigid social expectations of the era.

Discussion often centers on the novel's role as a precursor to the domestic realism found in later works by Jane Austen. Readers frequently highlight the extreme moral perfection of the title character, which serves as both a point of admiration and a source of debate regarding narrative realism. Critics often analyze the effectiveness of the epistolary format in capturing the nuances of social pressure and the internal lives of the female characters. The pacing is noted for its methodical nature, reflecting the author's commitment to exhaustive psychological detail and ethical instruction. Many readers appreciate the work for its historical significance in the development of the English novel, even as they acknowledge the density of its prose.