Joan Delano Aiken was an English writer specializing in supernatural fiction and children's alternative history novels. In 1999, she was awarded an MBE for her services to children's literature.

Her novel The Whispering Mountain, published by Jonathan Cape in 1968, won the Guardian Children's Fiction Prize, and she was a commended runner-up for the Carnegie Medal recognizing the year's best children's book by a British writer. She also won an Edgar Allan Poe Award in 1972 for Night Fall.

Born in Rye, East Sussex, she came from a family of writers, including her father, the poet Conrad Aiken, and her sister, Jane Aiken Hodge. Her mother, Jessie MacDonald, was a graduate of Radcliffe College. Joan Aiken was homeschooled by her mother, later attending Wychwood School, Oxford (1936-1940), but never attended university.

Joan began writing stories at an early age, with her first stories broadcast by the BBC in her early twenties. In 1945, she married journalist Ronald George Brown, with whom she had two children before his death in 1955. She remarried in 1976 to New York painter Julius Goldstein, who died in 2001.

She worked for the United Nations Information Office in London from 1943 to 1949, and joined Argosy magazine after her first husband's death, where she occupied various editorial roles and published her early short stories.

During her lifetime, she published numerous books annually, predominantly children's books and thrillers, along with articles, forewords, and essays on children's literature and Jane Austen's work. She passed away in her home in Petworth, West Sussex, at the age of 79.