Duncan Idaho is a fictional character in the Dune universe created by Frank Herbert. He was introduced in the first novel of the series, 1965's Dune, and became a breakout character. He was revived in 1969's Dune Messiah. He is the only character to feature in all six of Herbert's original Dune novels.

Dune is a 1965 epic science fiction novel by American author Frank Herbert, originally published as two separate serials in Analog magazine. It tied with Roger Zelazny's This Immortal for the Hugo Award for Best Novel and won the inaugural Nebula Award for Best Novel in 1966. It is the first installment of the Dune Chronicles. It is one of the world's best-selling science fiction novels.