What is the title of C.S. Lewis’s first published science-fiction novel?

C.S. Lewis’s first published science-fiction novel was Out of the Silent Planet.

Published in 1938, the novel is the first volume of Lewis’s Space Trilogy, also called the Ransom Trilogy. Its protagonist, Dr. Elwin Ransom, is kidnapped and taken to Malacandra, the planet humans call Mars. There he encounters intelligent inhabitants and learns that Earth is regarded as a fallen or troubled world.

The book combines planetary adventure with linguistic, theological, and philosophical ideas. Lewis’s depiction of Mars was influenced by older traditions of speculative fiction, but it also responds to modern concerns about colonialism, scientific power, and humanity’s moral condition.

The two later novels in the trilogy are Perelandra, published in 1943, and That Hideous Strength, published in 1945. Readers sometimes identify Perelandra as the first book because it is especially prominent in discussions of the trilogy, but Out of the Silent Planet clearly comes first in publication order.