David McDowall Hannay (25 December 1853 – 29 May 1934) was an English naval historian.
David Hannay was educated at Westminster School, and then joined his father, who was British consul in Barcelona, as vice-consul.
His first book was a monograph on Admiral Robert Blake, and he contributed several other works to various series of naval biographies.
In addition, his interest in Spain led to a study of its literature and he became a recognized authority on Spanish affairs.
[1] Hannay was an original member of the Navy Records Society on its formation in 1893, and due to his research efforts, and his lectures at the Royal Naval College, Greenwich, he became recognized as a leading scholar and historian on naval affairs.