Half Broke Horses is a 2009 novel by American writer Jeannette Walls detailing the life of her grandmother, Lily Casey Smith.

A woman of many talents, Lily earns extra money at various points in her life by playing poker, selling bootleg liquor, and riding in horse races.

Half Broke Horses depicts the freedom of rural life, its joys and struggles, and celebrates the courage and spirit of its protagonist, Lily Casey Smith.

Walls says the book is “in the vein of an oral history, a retelling of stories handed down by my family through the years, and undertaken with the storyteller’s traditional liberties.”[2] In The New York Times Book Review, critic Liesl Schillinger wrote, "Through the adventures of Lily Casey — mustang breaker, schoolteacher, ranch wife, bootlegger, poker player, racehorse rider, bush pilot and mother of two — Walls revisits the adrenaline-charged frontier background that gave her own mother a lifelong taste for vicissitude.

Rose Mary eventually found an anchor in the form of her daughter — the third generation of a line of indomitable women whose paths she has inscribed on the permanent record, enriching the common legend of our American past.