An "original character" created by the author, they may be a totally made up character or based on a living person. OC's are a creative way of expanding a fandom bringing their writer's own personal touch on a fandom. OC's give a reader a little insight into someone's imagination and can be amazing #StandUpForOCs
Stands for "original character." A character created by a fanfic author or roleplayer. Said created character does not belong to the canon cast but is inserted anyway for entertainment.
Many OCs appear as long-lost family members, past lovers, or exchange students. These background stories provide alibis for the sudden appearance and previous absences of the OC.
OC may also stand for "other character," in this case representing an extremely minor character, introduced or mentioned but not extremely active in an original series.