Marvin Herman Scilken (December 7, 1926 – February 2, 1999) was an American librarian and a leader in the field of library science during the 20th century. Scilken dedicated his life to bringing awareness to libraries and improving services for patrons. He encouraged libraries to take a more practical approach to librarianship and to consider libraries as a house of books rather than information centers. In 1999, American Libraries named him one of the "100 Most Important Leaders We Had in the 20th Century".