Susan Mary Cooper was born on 23 May 1935. She is an English author of children's books, best known for The Dark Is Rising, a contemporary fantasy series set in England and Wales. This series incorporates British mythology, such as the Arthurian legends and Welsh folk heroes. Her significant contributions to children's literature have been widely recognized. In 2012, she won the lifetime Margaret A. Edwards Award from the American Library Association, acknowledging her contribution to writing for teens. Furthermore, in the 1970s, two of the five novels in the The Dark Is Rising series were named the year's best English-language book with an "authentic Welsh background" by the Welsh Books Council. In 2024, she was named the 40th Damon Knight Memorial Grand Master by the Science Fiction and Fantasy Writers Association, in recognition of her significant contributions to the literature of science fiction and fantasy.

Cooper's journey as a writer began in Buckinghamshire, an area that was green countryside then but has since become part of Greater London. Growing up, she developed a fervent love for reading, a passion she shared with her younger brother, who also pursued a career in writing. Her academic journey led her to Oxford, where she made history by becoming the first woman to edit the university's newspaper. Following her graduation, she worked as a reporter and feature writer for London's Sunday Times, with James Bond creator Ian Fleming as her first boss.

Her literary career took off when she wrote her first book for young readers, Over Sea, Under Stone, in response to a publishing house competition. This book laid the groundwork for her critically acclaimed five-book fantasy sequence, The Dark Is Rising. Cooper's latest book is the YA novel Ghost Hawk (2013).