Sylvia Louise Engdahl (born November 24, 1933) is an American writer, known best for science fiction.
Her debut novel Enchantress from the Stars, published by Atheneum Books in 1970, was the 1971 Newbery Honor Book (see Newbery Medal), was a Geffen Award finalist in 2008, Best Translated YA Book, and she won the Phoenix Award for that work twenty years later.
Among 73 Library of Congress Online Catalog records of books created by Engdahl through 2014 (which may include multiple editions of some), all but the first 16 are nonfiction anthologies she edited while working as a freelance editor.
Engdahl wrote six science fiction novels published from 1970 to 1981 by Atheneum, all of which have been republished in the 21st century.
Enchantress from the Stars has also been runner-up for a few awards and has been named to several book lists.