Pottermaniac

plural Pottermaniacs

1. One who loves the Harry Potter series of books and films.

   The launch of the fifth book, for instance, involved only one personal appearance, when JKR read extracts to 4,000 carefully selected Pottermaniacs in the Albert Hall.

   2007, Bernard Cova, Robert Kozinets, & Avi Shankar, Consumer Tribes, Butterworth-Heinemann, →ISBN

   2 more examples

   J. K. Rowling's Harry Potter and the Goblet of Fire (Bloomsbury; 636 pages) would have sold millions of copies had its publishers simply dumped them in bookstores, unannounced, and then got out of the way as word of mouth spread among stampeding Pottermaniacs.

   2000 July 24, Paul Grey, “Harry's Magic is Back Again”, in Time

   If you are a Pottermaniac, this is the month for you. "Harry Potter and the Order of the Phoenix" opens today, and on July 21 the seventh and final Potter tome lands with a thud at your local bookstore.

   2007 July 12, Peter Rainer, “'Phoenix' rising: Harry Potter and the abridged tome”, in The Christian Science Monitor

   Synonyms: Potterhead, Potterholic, Potterite, Potterphile