Oberndorf, Charles,
--Oracle, September, 1996.

O'Donnell, Kevin, Jr.,
--The Dead of Winter, #15, May, 1979.
--The Raindrop's Role, #21, November, 1979.
--also see Longyear, Barry B., and Kevin O'Donnell, Jr.

Ore, Rebecca,
--Ocean Hammer, January, 1993.
--Hypocaust & Bathysphere, January, 1995. (novella)
--Scarey Rose in Deep History, #258, June, 1997.
--Collected Ogoense, #262-#263, October-November, 1997. (novelette)

Osgood, Gary R.,
--To Sin Against Systems, #4, Winter, 1977.
--The Last Master of Limericks, November-December, 1978.