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, Delaney initially worked as a teacher before transitioning to writing. He authored science fiction and fantasy novels under the pen name J. K. Haderack. After struggling in the adult book market, he found success with children's literature, beginning with The Spook's Apprentice in 2004, which sold over 3 million copies and won multiple awards. It was adapted into a play, the feature film Seventh Son, and a French graphic novel.

The Spook's Apprentice marked the start of Delaney's acclaimed Spook's series, eventually encompassing 20 books and additional related works. After the series' second book, he retired from teaching to focus on writing full-time. Delaney also published other children's series, including the science fiction and fantasy trilogy Arena 13 and the dark fantasy duology Aberrations.

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