Mystery at Lynden Sands is a 1928 detective novel by the British author Alfred Walter Stewart, published under his pseudonym J.J. Connington. It is the third in a series of novels featuring the Golden Age Detective Chief Constable Sir Clinton Driffield. It was published in London by Gollancz and Boston by Little, Brown and Company. It received a generally positive critical reception, with one reviewer going so far as to say it "may just fail of being the best detective story of the century" comparing it to The Cask and The Mysterious Affair at Styles.