O'Brien, Fitz-James,
--What Was It? December, 1925. ** (reprint)
--The Dragon Fang, July, 1927. (reprint)
--The Diamond Lens, April, 1929. (reprint)
--The Lost Room, October, 1929. (reprint)
--The Pot of Tulips, May, 1933. (reprint)
--The Wondersmith, July, 1935. (reprint)

O'Donnell, Elliott,
--The Ghost-Table, February, 1928.
--The Haunted Wood of Adoure, July, 1930.
--One Christmas Eve, July, 1934.

O'Kelley, Raymond F.,
--The Man Who LIved, September, 1941.

Oliver, Anton M.,
--The Living Nightmare, April, 1923.

Oliver, Douglas,
--The Last Man, December, 1925.

Olsen, Alice,
--Winter Night, May, 1940.

Olson, Ted,
--The Conquering Will, April, 1923.

O'Neail, N. J.,
--The Gallows Tree, December, 1929.
--The Flame-Fiend, September, 1930.
--Devouring Shadows, February, 1932.

O'Neil, Francis J.,
--The Japanese Tea Set, November, 1952.

Oppenheim, E. Phillips,
--The Tower Ghost, September, 1926.

Ordover, John,
--All Flesh Is Clay, #307, Summer, 1993. (short short)

Ore, Rebecca Brown,
--The Barbarian Queen, #299, Winter, 1990/1991. (poem)

Oursler, Will Charles,
--Mandolin, June, 1934.

Overton, Wilis,
--The Fantasmal Terror, April, 1928.

Owen, Frank,
--The Man Who Owned the World, October, 1923.
--The Open Window, January, 1924.
--Shadows, April, 1924.
--The Man Who Lived Next Door to Himself, May-June-July, 1924.
--Hunger, February, 1925.
--The Wind That Tramps the World, April, 1925.
--Black Hill, June, 1925.
--The Lantern-Maker, August, 1925.
--The Yellow Pool, October, 1925.
--The Fan, December, 1925.
--The Silent Trees, May, 1926.
--Seven Minutes, October, 1926.
--The Dream Peddler, January, 1927.
--The Blue City, September, 1927.
--The Purple Sea, February, 1928.
--The Tinkle of the Camel's Bell, December, 1928.
--The Ox-Cart, December, 1933.
--Pale Pink Porcelain, December, 1934.
--The Man Who Would Not Die, February, 1936.
--The Poppy Pearl, February, 1937.
--The Mandarin's Ear, August, 1937.
Owen, Frank, (continued)
--On Pell Street, July, 1940.
--By What Mystic Mooring, May, 1941.
--The March of the Trees, March, 1942.
--For Tomorrow We Die, July, 1942.
--The Lips of Caya Wu, November, 1942.
--Quest of a Noble Tiger, January, 1943.
--The Man Who Amazed Fish, May, 1943.
--The Street of Faces, July, 1943.
--Death in a Gray Mist, September, 1943.
--The Long Still Streets of Evening, September, 1944.
--The Three Pools and the Painted Moon, September, 1950.
--The Gentleman and the Scarlet Umbrella, January, 1951.
--The Unicorn, November, 1952.
--The Wind That Tramps the World, Fall, 1981. (reprint)

Owens, Elwin J.,
--Mystery River, May-June-July, 1924.
--Six Bearded Men, November, 1924.
--Black Temple Band, December, 1924.
--Dead in Three Hours, March, 1926.
--Knights of the Red Owl, April, 1926.

Ozment, Nick,
--If I've Ever Stumbled, #322, Winter, 2000/2001. (poem)
--Roach Phobia, #327, Spring, 2002. (poem)