Each year, the ALA's Office for Intellectual Freedom compiles a list of the top ten most frequently challenged books in order to inform the public about censorship in libraries and schools. The ALA condemns censorship and works to ensure free access to information.
A challenge is defined as a formal, written complaint, filed with a library or school requesting that materials be removed because of content or appropriateness. The number of challenges reflects only incidents reported. It is estimated that for every reported challenge, four or five remain unreported.
The ALA Office for Intellectual Freedom tracked 729 challenges to library, school, and university materials and services in 2021. Of the 1597 books that were targeted, here are the most challenged, along with the reasons cited for censoring the books: