What was the title of J.R.R. Tolkien’s first published book?

J.R.R. Tolkien’s first published book was The Hobbit. George Allen & Unwin published it in 1937, and it became the author’s breakthrough work.

The story follows Bilbo Baggins, a hobbit who leaves his comfortable home to join Thorin Oakenshield’s company on a journey toward the Lonely Mountain. Their goal is to reclaim a treasure guarded by the dragon Smaug.

Tolkien had already published scholarly work and shorter pieces before The Hobbit, but this was his first book-length work of imaginative fiction. Its success led the publisher to ask for another story about hobbits, which eventually developed into The Lord of the Rings.

The Hobbit is sometimes treated as though it was planned from the beginning as the first volume of The Lord of the Rings. Tolkien instead wrote it as a more self-contained children’s adventure, and its tone and details differ from the later epic. The two works were connected more fully as Tolkien revised them.