| Abbreviation | Definition |
|---|---|
| OCC | Overlake Christian Church |
| OCCA | Old Catholic Church of America |
| OCCA | Orthodox Catholic Church of America |
| OCCA | Oxford Centre for Christian Apologetics |
| OCCB | Ontario Conference of Catholic Bishops |
| OCCI | Orthodox Christian Counseling Institute |
| OCCR | Online Chinese Christian Resources |
| OCD | Discalced Carmelite Order |
| OCD | Order of Carmelites Discalced |
| OCDA | Orthodox Christian Deaf Association |
| OCDS | Secular Order of Discalced Carmelites |
| OCEAN | Openess/restiveness, Conscientousness/irresponsible, Extraversion/introversion, Agreeableness/irritibility, Neuroticism/stability |
| OCEC | Oregon City Evangelical Church |
| OCEC | Orthodox Christian Education Commission |
| OCF | Oceanside Christian Fellowship |
| OCF | Officers Christian Fellowship |
| OCF | Orthodox Christian Fellowship |
| OCF | Orthodox Christian Foundation |
| OCF | Ovearseas Christian Fellowship |
| OCF | Overseas Christian Fellowship |