The Mammoth Book of Best New Horror is an anthology series published annually by Constable & Robinson since 1990. In addition to the short stories, each edition includes a retrospective essay by the editors. The first six anthologies were originally published under the name Best New Horror before the title was changed beginning with the seventh book.
The first five books in the series were edited by Stephen Jones and Ramsey Campbell; beginning with the sixth book in 1995 they have been edited solely by Stephen Jones.
Books from the anthology series have been nominated for the World Fantasy Award for Best Anthology. The first book in the series won the 1991 award, and the twelfth volume was nominated for the 2002 award.