How many novels are in C.S. Lewis’s Space Trilogy?

C.S. Lewis’s Space Trilogy contains three novels.

The trilogy consists of Out of the Silent Planet, Perelandra, and That Hideous Strength. The first book appeared in 1938, the second in 1943, and the third in 1945. Together, they combine planetary adventure, philosophical debate, Christian themes, and warnings about the misuse of science and power.

Elwin Ransom is the central character of the first two novels and returns in the third. The books move from interplanetary exploration to a conflict involving Earth’s institutions, showing Lewis’s shift from traditional space adventure toward social and intellectual speculation.

The work is also called the Ransom Trilogy, after its protagonist. It is not the same as Lewis’s Narnia series, which contains seven novels and is aimed more directly at children. The two series share imaginative world-building but differ greatly in setting, tone, and intended audience.