Joseph Henry Delaney (25 July 1945 – 16 August 2022) was an English author, best known for his children's dark fantasy series, Spook's, which was inspired by the folklore, history, and geography of Lancashire. The series has been published in 30 countries, achieving sales of over 4.5 million copies.

Born in Preston, Lancashire, in 1945, Delaney initially pursued a career in teaching. He later turned to writing science fiction and fantasy novels under the pen name J. K. Haderack. After facing challenges in the adult book market, Delaney found success with children's literature, starting with The Spook's Apprentice in 2004. This book became a bestseller, selling over 3 million copies and winning multiple awards. It has been adapted into a play, a feature film titled Seventh Son, and a French graphic novel.

The Spook's Apprentice was the beginning of the acclaimed Spook's series, which ultimately included 20 books and other works set in the same universe. Following the second book's publication, Delaney retired from teaching to write full-time. He also created other children's series, such as the science fiction and fantasy trilogy Arena 13 and the dark fantasy duology Aberrations.

Delaney passed away in Manchester in 2022 at the age of 77. His final book, Brother Wulf: Wulf's War, was published posthumously the following year.