Joseph Henry Delaney (25 July 1945 – 16 August 2022) was an English author best known for his children's dark fantasy series, Spook's, 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 started his career as a teacher, who also authored science fiction and fantasy novels under the pen name J. K. Haderack. After struggling to find success as an author of books for adults, Delaney transitioned to writing children's books under his real name, beginning with the publication of The Spook's Apprentice, in 2004. The book was widely successful, selling over 3 million copies and winning multiple awards. It has been adapted into a play script, the feature film Seventh Son, and a graphic novel.

The Spook's Apprentice marked the start of his highly acclaimed Spook's series, which eventually encompassed 20 books, along with several other works set in the same universe. After the publication of the series' second book, Delaney retired from teaching to become a full-time writer. In 2014, The Spook's Apprentice was adapted into both a play script and the feature film Seventh Son. Additionally, Delaney published two other series for children: the science fiction and fantasy trilogy Arena 13, and the dark fantasy duology Aberrations.

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