Karen Marie Moning was born in Cincinnati, Ohio, the daughter of Anthony R. Moning and Janet L. Moning. Moning graduated from Purdue University with a Bachelor's degree in Society and Law. Before becoming a full-time writer, she worked as a bartender, a computer consultant, and an insurance specialist.

 

Moning began her career writing paranormal romance set in Scotland but as she became increasingly fascinated with Celtic mythology, she switched genres to Urban Fantasy and location to Dublin, Ireland, so she could focus on the Tuatha Dé Danann, or Fae—an ancient race of immortal beings who have lived secretly among humans for millennia.