The Circular Staircase is a mystery novel by American writer Mary Roberts Rinehart. The story follows dowager Rachel Innes as she thwarts a series of strange crimes at a summer house she has rented with her niece and nephew. The novel was Rinehart's first bestseller and established her as one of the era's most popular writers. The story was serialized in All-Story for five issues starting with the November 1907 issue, then published in book form by Bobbs-Merrill in 1908.