Elizabeth Janet Gray was born on October 6, 1902, in Philadelphia, to a Scottish father and a Quaker mother whose family had preceded William Penn to America. From both sides came a rich tradition of song and story, and Gray's writings reflect a devotion to history. She attended the Germantown Friends School and began her literary career with a story published in the Young Churchman. She earned two dollars for the work.

Entering Bryn Mawr College before she was seventeen, Gray completed college by the age of twenty and spent a year tutoring, writing short stories, and receiving rejection slips. She obtained a degree in library science from the Drexel Institute, but soon realized that her life's work lay in writing books.

In 1929 Gray married Morgan Vining, an administrator at the University of North Carolina, and she combined housekeeping with writing and teaching. Meggy Macintosh and Jane Hope came from her years in North Carolina, which ended with her husband's death in an automobile accident in 1933. After a brief stay in Washington, D.C., Gray returned to Philadelphia to live with her mother and her older sister. Many of her best known titles were published in the next ten years, including the Newbery Award-winning Adam of the Road. In 1934 Gray returned to the Quaker faith of her mother's family, joining the Society of Friends. She says that religion provided new strength and meaning for her life at a time when she desperately needed both.

During World War II, she joined the staff of the American Friends Service Committee in Philadelphia and spent nearly two years writing reports and articles. In 1946 the emperor of Japan sought an American Christian woman to teach English to the crown prince. Gray was appointed tutor to Crown Prince Akihito, and she lived in Japan until 1950. After her return to the U.S., Gray became a popular public speaker and resumed her writing career, recounting her time in Japan in Windows for the Crown Prince (1952), published under the name Elizabeth Gray Vining. Although written for adults, younger readers may also enjoy the book's insights into Japanese culture.

Gray has been awarded fourteen honorary degrees from various universities. In addition, she has won many honors, including the New York Herald Tribune Festival award in 1945 for Sandy, the Third Order of the Sacred Crown from Japan in 1950, and the Women's National Books Association Skinner Award in 1954. Gray also served for many years on the board of trustees for Bryn Mawr. She currently lives in Pennsylvania.