Kelley Armstrong, born Kelley L. Armstrong on 14 December 1968, is a prolific Canadian writer, who has made a significant mark in the fantasy genre since her debut in 2001. Armstrong's literary universe is expansive, with thirty-one fantasy novels under her belt. Her work includes thirteen novels in her Women of the Otherworld series, five in the Cainsville series, six in the Rockton series, three in both her Darkest Powers and Darkness Rising trilogies, and three in the Age of Legends series. Additionally, she has penned three stand-alone teen thrillers, three middle-grade fantasy novels in the Blackwell Pages trilogy (co-authored with Melissa Marr), and the Nadia Stafford trilogy, which ventures into crime novels.

Alongside her novels, Armstrong has contributed several serial novellas and short stories set in the Otherworld series, many of which are accessible for free on her website. Her influence extends beyond the page, with her Women of the Otherworld series being adapted into the Canadian television series Bitten, which aired for three seasons on Space and SyFy starting in 2014.

Before she could even write, Armstrong was already telling stories. Her early attempts were noted for their unique twist on typical narratives, featuring undead girls and evil dolls instead of the expected girls and dolls. Despite attempts to guide her towards more "normal" stories, Armstrong's fascination with the paranormal and supernatural realms prevailed. She continues to enthrall readers with tales of ghosts, demons, and werewolves from her "basement writing dungeon." Armstrong resides in southwestern Ontario with her husband, children, and a menagerie of pets.