The Thirty-Nine Steps is a 1915 adventure novel by the Scottish author John Buchan, first published by William Blackwood and Sons, Edinburgh. It was serialized in All-Story Weekly issues of 5 and 12 June 1915, and in Blackwood's Magazine between July and September 1915, before being published in book form in October of that year. It is the first of five novels featuring Richard Hannay, an all-action hero with a stiff upper lip and a knack for getting himself out of tricky situations.

John Buchan, 1st Baron Tweedsmuir was a Scottish novelist, historian, and Unionist politician who served as Governor General of Canada, the 15th since Canadian Confederation.