HOST & ASSISTANTS	ACTOR	MEDIA	TITLE
Observer	Bill Corbett Paul Chaplin	Television	Mystery Science Theater 3000
Octavian Hallow	Frank Wilmoth	Television	The Haven Falls Horror Fixx (Monster Channel)
Octavian Hallow	Frank Wilmoth	Television	New England Horror Hosts Takeover (The Monster Channel)
Officer Not-So-Friendly	Paul Dancer	Television	Zomboo's House of Horror Movies (KOLO-TV)
Old Crone	Beverly Beaton	Direct-To_Video	Tales From The Grave Tales From The Grave, Volume 2
Old Nancy	Adelaide Fitz-Allen	Radio	The Witch's Tale (WOR-Radio)
Old Nancy	Martha Wentworth	Radio	The Witch's Tale (WOR-Radio)
Old Nancy	Miriam Wolfe	Radio	The Witch's Tale (WOR-Radio)
Ole Anderson	Ken Kennedy (Kenneth Sydness)	Television	Weirdo Theater (WDAY)
Olivia Harker	Samantha Marie	Internet	Devilla's Midnight Movie Mortuary
Oliver	Chris McCabe	Television	Oliver's Twisted Bargain Basement Midnight Movie Stoner Friendly Freak Show
Oliver "The Caretaker" Collins	Oliver Collins	Television	Spine Chilling Cinema
Omar	Rondo McGrabe	Internet	Chester Grim's Mausoleum
Omentor	Raymond Edward Johnson	Radio	Tales of Tomorrow
Oogsley	Brandon Lunday	Television	Chiller Cinema Dr. Gangrene's Chiller Cinema Mad Movie of the Week
Ookie	David Hartman	Internet	Thriller Chiller Theatre
Original Cyn	Cyan Renteria	Television	FrightMare Theater (Spydar TV)
Original Cyn	Cyan Renteria	Television	Pale Moonlight Theater (Spydar TV)
Orlok	Joe Pinkerton	Television	Baron Creepy's Theatre Macabre
Ormon Grimsby	Craig Vance (Roger Kongstein)	Television	Monster Creature Feature (Time Warner Cable)
Ormsby's Deceased Mother	?	Television	Ormsby's Cinema Insane
Orson Welles (Host)	Orson Welles	Television	Scene of the Crime
Orville	Ronny Bom	Television	Shock Theatre (WBKB-TV)
Oscar The Ogre	David (Dave) Ivey	Television	Wolfman Mac's Chiller Drive-in (WMYD TV)
Otis Prometheus	Isaiah Wilson	Internet	Shack of Horrors
Otis The Kritter Gitter	?	Television	Dr. San Guinary's Creature Feature
Otto	?	Television	It Came from the Basement