Cate Tiernan is the pen name of Gabrielle Charbonnet, an American author born on July 24, 1961. She is best known for her Sweep series, which follows the Wiccan adventures of high school students. The series is sold under different names internationally, including the Wicca series in the UK, Belgium, The Netherlands, and Australia, and as White Magic (Magie Blanche) in Italy and France.

Under her real name, Gabrielle Charbonnet, she is known for children's book series such as Princess, American Gold Gymnasts, and Disney Girls. In 2008 and 2009, she collaborated with James Patterson on two young adult novels, Sundays at Tiffany's and Witch & Wizard.

Tiernan was born in New Orleans, LA, a city with a rich and exotic culture that deeply influenced her. She has lived in both New Orleans and New York, and her career started in publishing in Manhattan.