Mary Ann Shaffer was an American writer, editor, librarian, and bookshop worker born in Martinsburg, West Virginia in 1934. She spent her career working in various roles connected to books and writing before achieving her greatest recognition late in life. Shaffer is best known for The Guernsey Literary and Potato Peel Pie Society, a novel she co-wrote with her niece Annie Barrows. The book was published posthumously, after Shaffer's death in 2008 in San Anselmo, California. The novel became widely successful and introduced her work to a broad audience despite being released after her passing.