Perelandra (also titled Voyage to Venus in a later edition published by Pan Books ) is the second book in the Space Trilogy of C. S. Lewis.

The story begins with the philologist Ransom, some years after his return from Mars at the end of Out of the Silent Planet. With angelic help, he travels to Venus, a new Garden of Eden with a new Adam and Eve, to oppose the diabolically inspired human physicist Professor Weston who is tempting the Eve figure. His mission accomplished, he returns, rather reluctantly, to Earth to continue the fight against the forces of evil on their own territory.

Perelandra was published in 1943, one year after A Preface to Paradise Lost, and it deals with many of the same issues: the value of hierarchy, the dullness of Satan, and the nature of unfallen sexuality, for instance. To an extent, it can be viewed as a commentary on Milton's poem but a commentary which is intelligible to a reader ignorant of the original.

In addition, one of the key sequences of the story is Ransom's descent into the underground caverns of the planet, followed by a period of physical and mental rest in a healing grove, and climaxing with a vision of the essential truth of life in the Solar System, and possibly of the nature of God: strongly parallelling the journeys of Dante in the Divine Comedy.

The third volume of the trilogy, That Hideous Strength, is set on Earth and, perhaps inevitably, has rather a different tone than the prior two volumes; Ransom is a key character but is "off-stage" for much of the action.