| Abbreviation | Definition |
|---|---|
| OIBM | Opportunity International Bank of Malawi |
| OIL | Overseas Investment Loan |
| OLB | Online Banking |
| OLBB | Online Banking for Business |
| OLTB | On Line To Bank |
| O-M | Organization and Methods |
| OMB | Only My Brothers- Oroville Mono Boys |
| OMF | Overseas Mortgage Finance |
| OMLB | Omaha Municipal Land Bank |
| ONB | Old National Bank |
| ONB | Olmsted National Bank |
| ONB | Omni National Bank |
| ONQ | Omittace is Not Quittance |
| OPCB | Ohlone Preserve Conservation Bank |
| OPSB | Old Private Sector Bank |
| ORCB | Oursan Ridge Conservation Bank |
| ORR | Obligatory Risk Ratio |
| ORRF | Overseas Remittance Request Form |
| OSB | Oklahoma State Bank |
| OSB | Ottawa Savings Bank |