The Year's Best Science Fiction: Thirty-First Annual Collection is an anthology of science fiction short stories edited by Gardner Dozois, the thirty-first volume in an ongoing series. It was first published in hardcover, trade paperback and ebook by St. Martin's Griffin in July 2014, with a book club edition co-issued with the Science Fiction Book Club issued in the same month. The first British edition was published in trade paperback by Robinson in November 2014, under the alternate title The Mammoth Book of Best New SF 27