Ransom is the surname of the hero of C.S. Lewis's Space Trilogy. The character's full name is Elwin Ransom, and he appears as the central human figure across the series.
The trilogy consists of Out of the Silent Planet, Perelandra, and That Hideous Strength. In the first novel, Ransom is transported to Malacandra, a planet that readers may identify with Mars. The later books place him in increasingly complex conflicts involving planetary powers, spiritual beings, science, and human society.
Ransom is a philologist, a scholar whose work involves language and literature. That profession is important to the first novel because communication across worlds is one of its central concerns. Lewis used the series to explore ideas about technology, morality, colonialism, and the relationship between science and spirituality.
The name can be confused with Weston or Devine, two other important characters in the first book. Ransom is not the trilogy's villain or its narrator; he is the recurring protagonist whose experiences link the three novels.