The Forbidden Book Catalog.
- Country: Japan
- Type: Cultural
- Website: www.project-index.net
- Update: 05-02
A Certain Magical Index (とある魔術の禁書目録(インデックス), A Certain Magical Index) is a Japanese light novel series written by Kazuma Kamachi, with the first Japanese book published in April 2004, which won the 2011 This Light Novel is Awesome! First Place of the Year honor.