G
- Lew Gallo ("The Rip Van Winkle Caper", "On Thursday We Leave for Home" and "The Hitch-Hiker")
- Ray Galvin ("One More Pallbearer") (uncredited)
- David Garcia ("The Passersby")
- Betty Garde ("The Odyssey of Flight 33" and "The Midnight Sun")
- Beverly Garland ("The Four of Us Are Dying")
- Jimmy Garrett ("The Night of the Meek") (uncredited)
- Susie Garrett ("Dead Man's Shoes") (uncredited)
- Kelton Garwood ("Five Characters in Search of an Exit")
- Larry Gates ("The Shelter")
- James Gavin ("Back There")
- Don Gazzaniga ("Caesar and Me")
- Dick Geary ("The Grave")
- Leonard P. Geer ("The Old Man in the Cave") (uncredited)
- Paul Genge ("Dust")
- Betty Lou Gerson ("Ring-a-Ding Girl")
- Raymond Gibbons ("Of Late I Think of Cliffordville")
- Connie Gilchrist ("In Praise of Pip")
- Tom Gilleran ("Black Leather Jackets")
- Larrian Gillespie ("The Night of the Meek") (uncredited)
- Jack Ging ("The Whole Truth")
- Everett Glass ("The Silence")
- Ned Glass ("A Passage for Trumpet" and "The Midnight Sun" (uncredited))
- Edmund Glover ("Person or Persons Unknown")
- Lisa Golm ("The Man in the Bottle")
- Maxine Cooper Gomberg ("And When the Sky Was Opened") (as Maxine Cooper)
- Thomas Gomez ("Escape Clause" and "Dust")
- Don Gordon ("The Four of Us Are Dying" and "The Self-Improvement of Salvadore Ross")
- Gerald Gordon ("In Praise of Pip" (uncredited))
- Susan Gordon ("The Fugitive")
- William D. Gordon ("Nervous Man in a Four Dollar Room" and "The Eye of the Beholder")
- Harold Gould ("Probe 7, Over and Out")
- Sandra Gould ("Cavender Is Coming" and "What's in the Box")
- Sherry Granato ("In His Image")
- Austin Green ("The Passersby")
- Raymond Greenleaf ("Back There")
- Dabbs Greer ("Hocus-Pocus and Frisby" and "Valley of the Shadow")
- Virginia Gregg ("Jess-Belle" and "The Masks")
- James Gregory ("Where Is Everybody?" and "The Passersby")
- Mary Gregory ("The Monsters Are Due on Maple Street, "The Lateness of the Hour", "The Shelter")
- Bethelynn Grey ("The Dummy") (uncredited)
- Duane Grey ("The Chaser" (uncredited) and "Dust")
- Vernon Gray ("People Are Alike All Over")
- Jack Grinnage ("The Mind and the Matter")
- Claire Griswold ("Miniature")
- George Grizzard ("The Chaser" and "In His Image")
- Lyn Guild ("The Monsters Are Due on Maple Street")
- Paul Gustine ("The Silence") (uncredited)
Read more about this topic: List Of The Twilight Zone (1959 TV Series) Guest Stars