Which Tolkien novel first introduces Tom Bombadil?

Tom Bombadil first appears in J.R.R. Tolkien’s The Fellowship of the Ring.

Bombadil enters the story during the early journey of Frodo, Sam, Merry, and Pippin through the Old Forest. After the Hobbits become trapped by the hostile tree known as Old Man Willow, Bombadil rescues them and brings them to his home with Goldberry.

The character is one of the most enigmatic figures in Tolkien’s fiction. He is presented as extraordinarily old and powerful within his own realm, yet he does not join the Fellowship or travel to Mordor. The One Ring also behaves unusually around him: Bombadil is not made invisible when he puts it on, and he shows little interest in its power.

Readers sometimes assume Bombadil originated in The Hobbit, but he does not appear there. Tolkien had written poems about Bombadil before The Lord of the Rings, and those earlier poems helped shape the character later included in the novel.