| OPI | Obesity Prevention Initiative 
| Others |
| OPI | Occupational Performance Issue
| Others |
| OPI | Odontorium Products Inc
| Others |
| OPI | Oenpelli, Northern Territory, Australia
| Others |
| OPI | Office of Performance Improvement
| Others |
| OPI | Office of Planning and Informatics
| Others |
| OPI | Office of Police Integrity
| Others |
| OPI | Office of Primary Interest
| Others |
| OPI | Office of Public Instruction
| Others |
| OPI | Office of Public Integrity
| Others |
| OPI | Office Products Inc
| Others |
| OPI | Office Products International
| Others |
| OPI | Office Properties Income
| Others |
| OPI | Officer of Principal Interest
| Others |
| OPI | Offline Processing and Integration
| Others |
| OPI | Ohio Penal Industries
| Others |
| OPI | Olivia Pope Investigations
| Others |
| OPI | Omnibus Personality Inventory
| Others |
| OPI | On Package Interconnect
| Others |
| OPI | One Piece Integration
| Others |
| OPI | Online Placement Instrument
| Others |
| OPI | Online Product Information
| Others |
| OPI | Open Payment Initiative
| Others |
| OPI | Open Perimetry Interface
| Others |
| OPI | Open Peripheral Interface
| Others |
| OPI | Open Platform Initiative
| Others |
| OPI | Open Platform Interface
| Others |
| OPI | Open Postscript Interface
| Others |
| OPI | Open Prepress Interface
| Others |
| OPI | Open Press Interface
| Others |
| OPI | Opening Package Inspection
| Others |
| OPI | Operating Performance Index
| Others |
| OPI | Operations Procedure Instruction
| Others |
| OPI | Opiates
| Others |
| OPI | Opioid Prescription Intervention
| Others |
| OPI | Optical Phusion Inc
| Others |
| OPI | Optimum Performance Institute
| Others |
| OPI | Optional Procedure Indicator
| Others |
| OPI | Oracle Programmatic Interface
| Others |
| OPI | Oral Presentation Initiative
| Others |
| OPI | Oral Proficiency Interview
| Others |
| OPI | Orbiter Payload Interrogator
| Others |
| OPI | Oregon Project Independence
| Others |
| OPI | Organic Performance Index
| Others |
| OPI | Organizational Performance Index
| Others |
| OPI | Orientation Professionals Institute
| Others |
| OPI | Orthodontal Products Incorporated
| Others |
| OPI | Other Peoples' Interviews
| Others |
| OPI | Ounce of Prevention Insurance
| Others |
| OPI | Our Private Interhouse
| Others |
| OPI | Outsource Partners International
| Others |
| OPI | Over the Phone Interpreter
| Others |
| OPI | Overall Pavement Index
| Others |
| OPI | Overall Performance Incentive
| Others |
| OPI | Oxygen Percentage Indicator
| Others |