| Abbreviation | Definition |
|---|---|
| OI | Open Interest |
| OI | Operating Income |
| OIA | Open Item Accounting |
| OIBD | Operating Income Before Depreciation |
| OIBDA | Operating Income Before Depreciation and Amortization |
| OIBIDA | Operating Income Before Depreciation And Amortization |
| OIC | Organismo Italiano di Contabilita (Italian Accounting Committee) |
| OIDMTC | Ontario Interactive Digital Media Tax Credit |
| OJ | Official Journal |
| OLA | On-Line Accounting |
| OLACEFS | Organization of Latin American and Caribbean Supreme Audit Institutions |
| OLE | Old Ledger Extension |
| OLE | On-Line Entry |
| OLER | On-Line Entry Requirements |
| OLJ | On- Line Journal |
| OLTAS | On-Line Tax Accounting System |
| OLTV | Original Loan To Value |
| OMB | Office of Management and Budget |
| OMC | Owner May Carry |
| OMMAS | Online Management Monitoring and Accounting System |