Joseph Henry Delaney 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 started his career as a teacher. He initially 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 became widely successful, selling over 3 million copies and winning multiple awards. It was adapted into a play script, the feature film Seventh Son, and a French 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. 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.