What is the name of Tolkien’s first published Middle-earth novel?

J.R.R. Tolkien’s first published Middle-earth novel was The Hobbit.

The Hobbit appeared in 1937 and introduced readers to Bilbo Baggins, a hobbit who joins Thorin Oakenshield and his company of dwarves. Their goal is to reclaim the Lonely Mountain and its treasure from Smaug. Gandalf accompanies and encourages the expedition, while Bilbo gradually becomes a resourceful adventurer.

The novel established many features later associated with Tolkien’s legendarium, including hobbits, dwarves, dragons, the wizard Gandalf and the Ring. Tolkien subsequently expanded the Ring’s role and connected the earlier adventure to the larger conflict in The Lord of the Rings.

The Silmarillion was published after Tolkien’s death in 1977, edited by Christopher Tolkien, and presents much older mythic material. The Lord of the Rings was written after The Hobbit and published in three volumes from 1954 to 1955. The Children of Húrin is also a posthumously published work drawn from First Age stories.