S
- Lee Sabinson ("The Whole Truth")
- Albert Salmi ("Execution", "A Quality of Mercy" and "Of Late I Think of Cliffordville")
- Robert Sampson ("Little Girl Lost")
- Hugh Sanders ("Judgment Night", "The Jungle" and "Of Late I Think of Cliffordville")
- Lee Hands ("The Fever")
- Joseph Sargent ("In His Image" (uncredited) and "Twenty Two" (uncredited))
- William Sargent ("The Parallel" and "Ninety Years Without Slumbering")
- Telly Savalas ("Living Doll")
- Arline Sax ("What You Need" and "Twenty-Two")
- Jeffrey Sayre ("To Serve Man" (uncredited) and "The Fever" (uncredited))
- William Schallert ("Mr. Bevis")
- Joseph Schildkraut ("Deaths-Head Revisited" and "The Trade-Ins")
- Norbert Schiller ("Mute") (uncredited)
- Henry Scott ("The Big Tall Wish" and "The Thirty-Fathom Grave")
- Jacqueline Scott ("The Parallel")
- Pippa Scott ("The Trouble With Templeton")
- Simon Scott ("The Last Flight")
- Vito Scotti ("Mr. Bevis" and "The Gift")
- Alexander Scourby ("The Last Flight")
- Scott Seaton ("Passage on the Lady Anne" (uncredited) and "The Silence" (uncredited))
- James Seay ("In His Image")
- Charles Seel ("He's Alive") (uncredited) and "The Hunt")
- Sarah Selby ("Caesar and Me")
- Milton Selzer ("Hocus-Pocus and Frisby" and "The Masks")
- Rod Serling ("A World of His Own") (as himself)
- Lenore Shanewise ("Kick the Can")
- William Shatner ("Nick of Time" and "Nightmare at 20,000 Feet")
- Norma Shattue ("Cavender Is Coming") (uncredited)
- David Sheiner ("The Thirty-Fathom Grave")
- Jacques Shelton ("The 7th Is Made Up of Phantoms") (uncredited)
- Orville Sherman ("The Hunt")
- Mercedes Shirley ("On Thursday We Leave for Home")
- Max Showalter ("It's a Good Life") (credited as Casey Adams)
- Roy N. Sickner ("Cavender Is Coming")
- Frank Silvera ("Person or Persons Unknown")
- Georgia Simmons ("The Bewitchin' Pool")
- Robert F. Simon ("No Time Like the Past")
- Doris Singleton ("A Kind of a Stopwatch")
- Penny Singleton ("Sounds and Silences")
- Max Slaten ("A Stop at Willoughby") (uncredited)
- Everett Sloane ("The Fever")
- Howard Smith ("A Stop at Willoughby" and "Cavender Is Coming")
- Loring Smith ("The Whole Truth" and "I Dream of Genie")
- Patricia Smith ("Long Distance Call")
- Robert Snyder ("One More Pallbearer") (uncredited)
- Abraham Sofaer ("The Mighty Casey")
- Vladimir Sokoloff ("Dust", "The Mirror" and "The Gift")
- Robert Sorrells ("The Mighty Casey")
- Olan Soule ("The Man in the Bottle" and "Caesar and Me")
- Douglas Spencer ("Mr. Dingle, the Strong")
- Don Spruance ("You Drive") (uncredited)
- Katherine Squire ("One More Pallbearer" and "In His Image")
- Tim Stafford (see Jeffrey Byron) ("The Bewitchin' Pool")
- Ted Stanhope ("Perchance to Dream") (uncredited)
- Edgar Stehli ("Long Live Walter Jameson")
- Robert Sterling ("Printer's Devil")
- Inger Stevens ("The Hitch-Hiker" and "The Lateness of the Hour")
- Marc Stevens ("Kick the Can") (uncredited)
- Naomi Stevens ("Mirror Image")
- Warren Stevens ("Dead Man's Shoes")
- Robert Stevenson ("The Midnight Sun" (radio announcer, uncredited) and "Showdown with Rance McGrew")
- Peggy Stewart ("The Shelter")
- Dean Stockwell ("A Quality of Mercy")
- Ron Stokes ("What's in the Box" (uncredited))
- George E. Stone ("Once Upon a Time")
- Harold J. Stone ("The Arrival")
- Judy Strangis ("The Bard")
- Tracy Stratford ("Little Girl Lost" (uncredited) and "Living Doll")
- Chet Stratton ("Miniature") ("The Mind and the Matter")
- Amzie Strickland ("The Monsters Are Due on Maple Street")
- Edson Stroll ("The Eye of the Beholder" and "The Trade-Ins")
- Diane Strom ("Static")
- Leonard Strong ("The Hitch-Hiker")
- Shepperd Strudwick ("Nightmare as a Child")
- Barbara Stuart ("A Thing About Machines")
- Laird Stuart ("The Changing of the Guard") (uncredited)
- Maxine Stuart ("The Eye of the Beholder")
- Lomax Study ("To Serve Man")
- Norman Sturgis ("What You Need")
- Joan Sudlow ("The Monsters Are Due on Maple Street")
- Alan Sues ("The Masks")
- John L. Sullivan ("What's in the Box" (uncredited))
- Liam Sullivan ("The Silence" and "The Changing of the Guard")
- Mark Sunday ("What You Need") (uncredited)
- Frank Sutton ("The Dummy")
- William Swan ("The Long Morrow")
- Harry Swoger ("Dead Man's Shoes")
- Albert Szabo ("The Man in the Bottle") (uncredited)
- Éva Szörényi ("Mute")
Read more about this topic: List Of The Twilight Zone (1959 TV Series) Guest Stars