Opal Irene Whiteley (December 11, 1897—February 16, 1992) was an American nature writer and diarist whose childhood journal was first published in 1920 as The Story of Opal in serialized form in the Atlantic Monthly, then later that same year as a book with the title The Story of Opal: The Journal of an Understanding Heart.
The diary gave Whiteley a celebrity status in her home state of Oregon, where she toured giving lectures on nature and the environment.
She lived her later life in England, where she committed herself to a psychiatric hospital in 1948; she spent the remainder of her life in psychiatric care until her death in 1992.
Whiteley's true origins and the veracity of her diary were disputed during her lifetime, and continue to be questioned today.