Galaxis Bright and Galaxis Dark Sister planets mentioned in the novella Nightdreamers. Dark was economically superior to Bright. The moon Verd orbited Bright.
Gallifrey is the home planet of the Time Lords. It was first seen (but not named) in The War Games and first named (but not seen) in The Time Warrior. It was thought to be destroyed in a Time War, wiping out nearly all of the Time Lord race. It was in fact saved by all of thirteen incarnations of the Doctor in the 50-year anniversary, the Day of the Doctor. It is trapped in a pocket universe. It has burnt-orange skies and snow-covered mountains, silver-leafed trees and red grass. Fragments of Gallifrey revolve around its system's two suns in the form of a ring of rocks and dust. The Time Lord council attempted to restore the planet beyond the Time War from within the time lock, using the Master and a white point star to form a physical connection beyond the time lock, but the Doctor destroyed the link.
Galsec Seven A planet mentioned in The Sontaran Experiment. It is where a human colony is located.
Gameworld Gamma is a lush, green world owned by Mr and Mrs Pakoo, as seen in the Doctor Who Adventures. It is used to hunt humans in the year five billion.
Gauda Prime A human colony planet in the Earth Empire. A tough place to live. Mentioned in Prisoner of the Daleks.
Gearon A Planet mentioned in Mission to the Unknown, set c.4000. This is also the name of one of the delegates in the Galactic Council.
Gidu A stormy planet mentioned in Nightmare of Eden. Gidu has a light pinkish-yellow atmosphere and has a wide variety of vegetation. Its surface is often bombarded by gale force winds.
Glasson Minor A planet mentioned in The Creature from the Pit.
Golobus Another planet mentioned in the Seventh Doctor story The Greatest Show in the Galaxy.
Gond Homeworld Unnamed planet of the humanoid Gonds, who were in the thrall of The Krotons.
Grajick Major One of the planets Rose and the Doctor visited. Mentioned in the episode Boom Town and also in Justin Richards Ultimate Monster Guide.
Granados Another planet that was destroyed by Zanak in The Pirate Planet.
Grått A world visited in the comic strip "The Whispering Gallery." Emotion is outlawed amongst the humanoid inhabitants of this rainy world, described as a dwarf planet.
Griffoth is the home planet of the Graske, and is seen in the interactive episode Attack of the Graske. It was one of the twenty-seven planets taken by the Daleks in The Stolen Earth.
Griophos A planet mentioned in Paradise Towers.
Grold Homeworld A small, hot planet with a rarefied atmosphere. Tidally locked, therefore lacking a day-night cycle. The Grold were flurosilicon-based, and appeared in The Eye of the Giant.
Grolon Yet another planet mentioned in The Greatest Show in the Galaxy.
Grundle is a planet mentioned in Carnival of Monsters. A swampy satellite of this planet is home to the vicious Drashigs.