Maggie Stiefvater (born Heidi Hummel on November 18, 1981) is a New York Times bestselling author known for her young adult fantasy series The Wolves of Mercy Falls and The Raven Cycle. An American writer, Stiefvater is also known for her novel The Scorpio Races. She combines her passion for storytelling with artistic pursuits, playing several musical instruments, most famously the bagpipes, and creating art in various media, particularly with colored pencils.

Stiefvater is an avid driver of vehicles and a dedicated reader. She shares her life in Virginia with her husband, two children, many dogs, a group of fainting goats, and an irascible tuner car.