A Pair of Blue Eyes is a novel by Thomas Hardy, published in 1873, first serialised between September 1872 and July 1873. It was Hardy's third novel, but the first to bear his name on publication. The book describes the love triangle of a young woman, Elfride Swancourt, and her two suitors from very different backgrounds. Stephen Smith is a socially inferior but ambitious young man who adores her and with whom she shares a country background. Henry Knight is the respectable, established, older man who represents London society. Although the two are friends, Knight is not aware of Smith's previous liaison with Elfride. Elfride finds herself caught in a battle between her heart, her mind and the expectations of those around her – her parents and society. When Elfride's father finds that his guest and candidate for his daughter's hand, architect's assistant Stephen Smith, is the son of a mason, he immediately orders him to leave. Knight, who is a relative of Elfride's stepmother, is later on the point of seeking to marry Elfride, but ultimately rejects her when he learns she had been previously courted. Elfride, out of desperation, marries a third man, Lord Luxellian. The conclusion finds both suitors travelling together to Elfride, both intent on claiming her hand, and neither knowing either that she is already married or that they are accompanying her corpse and coffin as they travel.

The heroine of the novel is a young Elfrid. She can easily charm anyone with the look of her blue eyes. In her life, two appear, a young architect and an experienced writer. Former friends become rivals, and Elfrida is faced with a painful choice.