The leader of the SS cadets maintaining the suspended animation equipment that contains Hitler and Professor Friedl. Karl and the other SS cadets had their growth stopped before adult hood, this meant that they did not age. Karl looked 15 years old, but was in actually 48.

He is the youngest of the Tomorrow People. He broke-out before the first series. He has extra telekinetic abilities. He leaves Earth to become an ambassador to the Galactic Federation.

Kenny lived near the Lab with his mother.

A KGB agent based at the Russian Embassy in London.

He reports to a senior KGB man. He was escorting Pavla on her visit to London to spy on the NATO conference.

Little is known of the Kleptons. They are not part of the Galactic Federation. They enslave planets for a short while, often using local children as workers and hostages. They normally select planets where there is a lower level of culture and the people do not have the technology to fight back. They only stay on a planet for a short while. On their travels they learned to speak English.

The Kleptons had enslaved the planet Gallia. The Tomorrow People managed to force the Kleptons to leave, and stranded them on a barren planet Stixus.

A race of non-telepathic bipedal aliens that enslave planets. It is believed that they eat humanoids alive.

The Kulthan build pyramids and hide Psi Damping Transmitters within them to block telepathic abilities. They then use the local inhabitants to capture telepaths who are then transported to the Kulthan ships in orbit. The telepaths are then stored until they can be collected.

The Kulthan once enslaved the Earth, but were forced to leave by the Galactic Federation approximately 6000 years ago. The Psi Damping Transmitter is housed within the Great Pyramid of Chaeops, but has recently stopped working, allowing the Tomorrow People's telepathic abilities to emerge.

The son of Tirayaan. He is next in line to become the ruler of Regoraa.

When the father-ship was being pulled towards the hole in space, Kwaan took the shuttle craft to try to get help from Regoraa. He became lost and drifted towards Earth and was rescued by the Tomorrow People.