A Lost Lady is a novel by American author Willa Cather, first published in 1923. It centers on Marian Forrester, her husband Captain Daniel Forrester, and their lives in the small western town of Sweet Water, along the Transcontinental Railroad. However, it is mostly told from the perspective of a young man named Niel Herbert, as he observes the decline of both Marian and the West itself, as it shifts from a place of pioneering spirit to one of corporate exploitation. Exploring themes of social class, money, and the march of progress, A Lost Lady was praised for its vivid use of symbolism and setting, and is considered to be a major influence on the works of F. Scott Fitzgerald. It has been adapted to film twice, with a film adaptation being released in 1924, followed by a looser adaptation in 1934, starring Barbara Stanwyck.

A Lost Lady begins in the small railroad town of Sweet Water, on the undeveloped Western plains. The most prominent family in the town is the Forresters, and Marian Forrester is known for her hospitality and kindness. The railroad executives frequently stop by her house and enjoy the food and comfort she offers while there on business. A young boy, Niel Herbert, frequently plays on the Forrester estate with his friend. One day, an older boy named Ivy Peters arrives, and shoots a woodpecker out of a tree. He then blinds the bird and laughs as it flies around helplessly. Niel pities the bird and tries to climb the tree to put it out of its misery, but while climbing he slips, and breaks his arm in the fall, as well as knocking himself unconscious. Ivy takes him to the Forrester house where Marian looks after him. When Niel wakes up, he's amazed by the nice house and how sweet Marian smells. He doesn't't see her much after that, but several years later he and his uncle, Judge Pommeroy, are invited to the Forrester house for dinner. There he meets Ellinger, who he will later learn is Mrs. Forrester's lover, and Constance, a young girl his age.

Willa Cather was an American author, best known for her novels detailing frontier life on the Great Plains. Although she is best known for O Pioneers and My Antonia, it was her 1922 novel One of Ours that won her the Pulitzer Prize for Literature. The author of twelve novels, three works of nonfiction, and nine collections of essays and short stories, she was the subject of the 2005 PBS documentary Willa Cather: The Road is All.