Dr. Elwin Ransom – The protagonist of the novel, Ransom is a philologist who finds himself on a journey against his will to a strange world he has never seen. He is portrayed as an average man with good intentions and his modest share of courage and ingenuity. An unlikely hero, Ransom rises to each challenge and comes into his own in this first installment of the trilogy.

Dr. Weston – A pure, hard scientist who has no respect for any forms of education other than physics and mathematics, Weston is a classic villain. He demonstrates foolish idealism and unsentimental megalomania, and has no respect for other cultures or traditions. His stubborn bigotry is juxtaposed with his immense knowledge of physics.

Devine – Weston’s scheming partner, Devine was an old boarding school enemy of Ransom’s. His main interest in Malacandra is the exploitation of her natural resources, especially the large gold deposits.

Hyoi – The Hross who first meets Ransom, Hyoi becomes very close with him, teaching him the ways of the Hrossa people and survival techniques on Malacandra. Hyoi is later shot and killed by Weston.

Hnohra – One of the members of Hyoi’s tribe, Hnohra plays a pivotal role in Ransom’s journey by teaching him the common language of the solar system.

Augray – The Sorn that befriends Ransom and teaches him the history of Malacandra, Augray carries Ransom to Meldilorn to meet with Oyarsa.

Oyarsa of Malacandra – The great Eldil controlling life on Malacandra, Oyarsa is a band of light that is just barely visible to the naked eye. He begins a friendship, if it can be called that, with Ransom as the philologist is preparing to leave Malacandra.