Cate Tiernan (born July 24, 1961) is the pen name of Gabrielle Charbonnet, an American author. Writing as Cate Tiernan, she is best known for her Sweep series, which follows the Wiccan adventures of a cast of high school students. The stories are sold as the Wicca series in the UK, Belgium, The Netherlands and Australia, and as White Magic (Magie Blanche) in Italy and France. Under her own name, she is chiefly known for children's books in the Princess, American Gold Gymnasts, and Disney Girls series. In 2008 and 2009, Charbonnet collaborated with author James Patterson on two "young adult" novels, Sundays at Tiffany's and Witch & Wizard.