O'Donnell, Kevin, Jr.,
--Shattered Hopes, Broken Dreams, January, 1976. (novelette)
--Hunger on the Homestretch, March, 1976.
--In Xanadu, November, 1976.
--A Meeting of the Minds, June, 1977.

O'Donnell, K. M., (Barry N. Malzberg)
--We're Coming Through the Window, August, 1967.
--The Market in Aliens, November, 1968. (short short)
--Shattered Hopes, Broken Dreams, January, 1976.

O'Donnevan, Finn, (Robert Sheckley, 1928- )
--Subsistence Level, August, 1954.
--Uncle Tom's Planet, December, 1954.
--Trap, February, 1956.
--Bad Medicine, July, 1956.
--A Wind Is Rising, July, 1957.
--Gray Flannel Armor, November, 1957.
--The Gun Without a Bang, June, 1958.
--Join Now, December, 1958.
--The Sweeper of the Lorcey, April, 1959.

Offutt, Andrew J.,
--Blacksword, December, 1959. (author's first professional publication)
--Ask a Silly Question, July, 1970.

O'Hearn, Martin,
--Rescue Room, September, 1978.

Otker, Zane,
--The Panama Canal, February, 1970.

Overstreet, Lee,
--Angel of Destruction, January, 1976. (novelette)