Which C.S. Lewis novel features the character Ransom visiting Malacandra?

Out of the Silent Planet is the C.S. Lewis novel in which Ransom visits Malacandra.

Published in 1938, Out of the Silent Planet is the first book of Lewis’s Space Trilogy. Its protagonist, Dr. Elwin Ransom, is abducted and taken to the planet Mars, which the inhabitants call Malacandra. The story combines planetary adventure, linguistic discovery, theology, and criticism of exploitative colonial attitudes.

Ransom learns that Malacandra is inhabited by several intelligent species and that its society differs sharply from the morally damaged Earth. Lewis uses the fictional planet to explore ideas about humanity, morality, language, and the relationship between scientific ambition and spiritual responsibility.

The next two books are Perelandra and That Hideous Strength. A common mix-up is to identify Perelandra as the Mars novel; Perelandra is the second volume and takes Ransom to a different planet.