If I am citing a film based on a literary work, should I include the name of the literary work’s author in my entry?
No. A film based on a book is a work of art in its own right, separate from the book. The author of the book should not be mentioned in the works-cited-list entry for such a film, unless the author contributed to the film in an identifiable way, like writing the screenplay. However, if the author of the book that provides the basis for a film is important to your discussion, you can mention the author in your prose.
The following provides an example of a works-cited-list entry for a film based on a book:
The Chronicles of Narnia: The Lion, the Witch, and the Wardrobe. Directed by Adam Adamson, screenplay by Ann Peacock et al., Walt Disney Pictures, 2005.
Note that the film in this entry is based on The Lion, the Witch, and the Wardrobe, by C. S. Lewis, but the name C. S. Lewis does not appear in the entry, because he did not contribute to the film. You might mention in your discussion of the film that Lewis wrote the source material.