Dora Jessie Shafe was born on 17 April 1913 in London, the younger of the daughters of Arthur Shafe, an insurance agent, and his wife Grace. For the sake of her mother's health, the family moved to the country when Dora was seven, and she began school in Chelsfield, near Orpington, Kent, and later joined her older sister at Bromley county school. When her father became a schoolmaster, Dora followed his example and undertook teacher training at Homerton College, Cambridge.

From 1933 to 1940 she taught in Middlesex, first at Hayes and then at Ealing. In 1940 she married Douglas Saint. The couple had one daughter, Jill.

After World War II she worked occasionally as a teacher, and began writing about schools and country topics for several magazines, including Punch and the Times Educational Supplement. She also worked as a scriptwriter for the BBC schools service.

From 1955 to 1996 Saint wrote a series of novels centered on two fictional villages, Fairacre and Thrush Green. The first Fairacre novel appeared in 1955, the last in 1996. The first Thrush Green novel appeared in 1959. The principal character in the Fairacre books, Miss Read, is an unmarried schoolteacher in a small village school, an acerbic and yet compassionate observer of village life. Saint's novels are wry regional social comedies, laced with gentle humour and subtle social commentary. Saint was also a keen observer of nature and the changing seasons.

The first three books (marked *) have been published in a single volume, Chronicles of Fairacre. The three Christmas books marked with ** have been published together.

The Market Square (1966) and The Howards of Caxley (1967) are set in the historical past of Caxley, the nearby market town to Fairacre where Fairacre people go from time to time. Fairacre and Beech Green, a nearby village, are mentioned. The events in these books end before the events of the first Fairacre book start.