Elizabeth Coatsworth was born May 31, 1893, to Ida Reid and William T. Coatsworth, a prosperous grain merchant in Buffalo, New York. She attended Buffalo Seminary, a private girls' school, and spent summers with her family on the Canadian shore of Lake Erie. She began traveling as a child, visiting the Alps and Egypt at age five. Coatsworth graduated from Vassar College in 1915 as Salutatorian. In 1916 she received a Master of Arts from Columbia University. She then traveled to eastern Asia, riding horseback through the Philippines, exploring Indonesia and China, and sleeping in a Buddhist monastery. These travels would later influence her writing.
Elizabeth Coatsworth died at her home in Nobleboro, August 31, 1986. Her papers are held in the Kerlan Collection at the University of Minnesota and Bowdoin College, Brunswick, Maine, with a small archive from late in her career in the de Grummond Collection at the University of Southern Mississippi. There is also a collection of her papers at the Maine Women Writers Collection held at the University of New England, Portland, Maine.