Hattie Big Sky is a children's historical novel by Kirby Larson, published in 2006.

The novel is set during World War I. Hattie Brooks, a sixteen-year-old orphan who has tired of being shuttled between relatives she hardly knows, receives a letter from an uncle who has recently died.

One difficulty Hattie faces is being called upon, as a loyal American, to shun her kind neighbors because of their German descent.

According to Sharon Morrison in School Library Journal: "Larson's vivid descriptions of the harshness of the work and the extreme climates, and the strength that comes from true friendship, create a masterful picture of the homesteading experience and the people who persevered."

"[3] Kathleen Odean in Booklist praised Larson: "Writing in figurative language that draws on nature and domestic detail to infuse her story with the sounds, smells, and sights of the prairie, she created a richly textured novel full of memorable characters.