The book was first published in September 1885 amid considerable fanfare, with billboards and posters around London announcing "The Most Amazing Book Ever Written". It became an immediate best seller. By the late 19th century explorers were uncovering lost civilizations around the world, such as Egypt's Valley of the Kings, the city of Troy, and the empire of Assyria. Africa remained largely unexplored and King Solomon's Mines, the first novel of African adventure published in English, captured the public's imagination.

The "King Solomon" of the book's title is the Biblical king renowned both for his wisdom and for his wealth. A number of sites have been identified as the location of the mines of Solomon, including the workings at Timna near Eilat, and many "fictional" locations.

Haggard knew Africa well, having penetrated deep within the continent as a 19-year-old during the Anglo-Zulu War and the First Boer War, where he had been impressed by South Africa's vast mineral wealth and the ruins of ancient lost civilizations being uncovered such as Great Zimbabwe. His original Allan Quatermain character was based in large part on the real-life adventures of Frederick Courtney Selous, the famous British big game hunter and explorer of Colonial Africa.[ These experiences provided Haggard's background and inspiration for this and many later stories.