- The Overlords are an alien race. They come to Earth in the late twentieth century and take control of the planet. They eliminate disease, war and hatred, and create a world government that broadens into a utopia. This peaceful mission is overseen by Karellen. Physically, the average Overlord is much taller and more built than a human, with large wings, horns on its head, and a barbed tail.
in-depth analysis of The Overlords.
- Karellen is one of the Overlords, an alien race that comes to Earth in the late twentieth century and takes control of the planet. Karellen is known by most humans as the "Supervisor." Like all Overlords, he is much taller and more built than a human, with large wings, horns on his head, and a barbed tail.
in-depth analysis of Karellen.
- Stormgren is the Secretary-General of the United Nations when the Overlords arrive on Earth. Stormgren is the only human to have any personal contact with the Overlords during the first few years of the Overlords' reign on Earth. He reports directly to Karellen once every few weeks.
- Wainwright is the leader of the Freedom League, a religiously based group that opposes Earth's domination by the Overlords, despite the Overlords' clearly friendly and beneficial attitude.
Peter Van Ryberg
- Stormgren's assistant and the deputy-general of the United Nations.
- An American working on building an interstellar spaceship.
- A scientist working on constructing an interstellar spaceship for the Soviet Union.
- Rupert Boyce is a "supervet," a veteranarian assigned to assist animals over thousands of acres of jungle. He is a friend of George Greggson. Boyce owns the world's largest library of paranormal research, something of great interest to the Overlords.
- George Greggson is a television production designer. He marries Jean Morrel, and their children are Jeffrey and Jennifer.
in-depth analysis of George Greggson.
- A woman with an interest in the paranormal, who may have some psychic powers herself. She marries George Greggson and has two children, Jeffrey and Jennifer.
- A young, brilliant man with a strong interest in astronomy and space exploration. He is bitter that the Overlords have never allowed mankind to explore space.
in-depth analysis of Jan Rodricks.
- An oceanographic scientist. Sullivan's lab is deep under the ocean. The Overlords often ask Sullivan to perform such tasks as stuffing entire whales for exhibition in the Overlords' museums on their homeworld.
- An Overlord. Rashaverak's speciality is psychological research, and he takes special interest in Rupert Boyce's library of paranormal research. Like all Overlords, he is much taller and more built than a human, with large wings, horns on his head, and a barbed tail.
- The son of George Greggson and Jean Morrel. Early in his childhood, Jeffrey has strange dreams and begins to exhibit amazing mental abilities.
- The daughter and youngest child of George Greggson and Jean Morrel. As a baby, Jennifer soon begins to exhibit the strange behavior of her brother Jeffrey.
- An Overlord who befriends Jan Rodricks on the Overlords' homeworld. Like all Overlords, he is much taller and more built than a human, with large wings, horns on his head, and a barbed tail.
- Also known as "the Inspector," Thanthalteresco is an Overlord that visits and examines the commune of New Athens. Like all Overlords, he is much taller and more built than a human, with large wings, horns on his head, and a barbed tail.
- "Joe" is a radical member of Wainwright's Freedom League. He abducts Stormgren in an attempt to learn more information about the Overlords.
- The alien being that the Overlords serve. The Overmind is not a creature of matter; it is not solid. It is a kind of "collective conscious," a massive entity of thought and energy that crosses the galaxy, and perhaps the universe, trying to "increase its awareness of the universe." It incorporates entire races into itself, eliminating their individuality while greatly enhancing their power.
in-depth analysis of The Overmind.