O Pioneers!, a novel by American writer Willa Cather, the first one of her Great Plains trilogy that also contains The Song of the Lark (1915) and My Antonia (1918).

The story is set at the turn of the 20th century. The Bergsons, a family of Swedish immigrants settles in the countryside near the fictional town of Hanover, Nebraska. Alexandra Bergson, the main heroine, inherits the family farmland when her father dies, and she devotes her life to making the farm a viable enterprise at a time when many other immigrant families are giving up and leaving the prairie. There are romance and prose of life of the first settlers.