How many books comprise Stephen King’s original seven-book Dark Tower series? The answer is 7.
The original sequence runs from The Gunslinger through The Dark Tower VII: The Dark Tower. Stephen King published the first volume in 1982 and completed the seventh in 2004, presenting those seven books as sections of one long, connected quest centered on gunslinger Roland Deschain and the mysterious Tower.
The counting can be confusing because King later added The Wind Through the Keyhole, published in 2012. That book is set between Wizard and Glass and Wolves of the Calla, so modern reference works may describe the series as having eight novels. It does not change the answer to a question specifically asking about the original seven-book series.
The seven core books are The Gunslinger, The Drawing of the Three, The Waste Lands, Wizard and Glass, Wolves of the Calla, Song of Susannah, and The Dark Tower. The series blends fantasy, horror, science fiction, and Western elements, while connecting to characters and events from several other King works.