| Acronym | Definition |
|---|
| OSS | Office of Strategic Services |
| OSS | Open Source Software |
| OSS | Open Sound System (Unix digital audio architecture) |
| OSS | Operations Support System(s) |
| OSS | Operatore Socio Sanitario |
| OSS | Operating System Service |
| OSS | Origin of the Solar System |
| OSS | Office of Student Services |
| OSS | Operations Support Squadron |
| OSS | Out of School Suspension |
| OSS | Ofte Stillede Spørgsmål (Danish: Frequently Asked Questions) |
| OSS | Off Screen (cinematography) |
| OSS | Open Source Shakespeare (website) |
| OSS | Operational Support System |
| OSS | Operational Support System (THREAT) |
| OSS | Office SharePoint Server (Microsoft) |
| OSS | Oh So Sweet |
| OSS | One Stop Shopping |
| OSS | Office Support Systems |
| OSS | Operational Storage Support |
| OSS | Operating System Services |
| OSS | Office Sharepoint Services |
| OSS | Other Shared Secret |
| OSS | Open Systems Specialists |
| OSS | Open Sound System |
| OSS | Onboard Support Software |
| OSS | Office Search System |
| OSS | Operations Systems Support |
| OSS | Open System Services |
| OSS | Office Sharepoint Server |
| OSS | Open Storage Solutions |
| OSS | Open Source Storage |
| OSS | on Site Service |
| OSS | Operation Support System |
| OSS | On Site Service(s) |
| OSS | On-Site Support (various organizations) |
| OSS | Open Source Society (software) |
| OSS | Orthopaedic Surgery Specialists (various locations) |
| OSS | Overhead Sign Structure (transportation; various locations) |
| OSS | Office of Space Science |
| OSS | Our Shared Shelf (book club) |
| OSS | Ossetic (linguistics) |
| OSS | Office of the Secretary of State |
| OSS | Operations Support Services |
| OSS | Operation Spartan Shield (US Army) |
| OSS | Office of Special Services |
| OSS | Overseas Scholarship Scheme (Petroleum Technology Development Fund) |
| OSS | Old Submarine (US Navy) |
| OSS | Operational Support Services |
| OSS | Optical Steadyshot (image stabilization technology) |
| OSS | Ottawa, Sandusky, Seneca (recycling; Ohio) |
| OSS | Online Service System (SAP) |
| OSS | Office Support System |
| OSS | Official Statistics System (New Zealand) |
| OSS | Online Subscription Service (various organizations) |
| OSS | Open Standard Solutions (Japan) |
| OSS | Outside Surface |
| OSS | Outside Storage |
| OSS | Online Shopping Survey (various organizations) |
| OSS | Optional State Supplementation |
| OSS | Operator Service System |
| OSS | OnSite Solutions |
| OSS | Off-Site Surveillance System (various organizations) |
| OSS | Onsite Sewage System |
| OSS | Old-Style Siamese (cats) |
| OSS | Over-The-Shoulder Shot (video photograpy) |
| OSS | Object Storage Server |
| OSS | Ontario Seniors Secretariat (Canada) |
| OSS | OnDO SIP Server |
| OSS | Officer Safety and Survival Training Program (US FEMA) |
| OSS | Operational Sequencing System (US Navy) |
| OSS | Occupy Sesame Street (satire) |
| OSS | Online Search Service |
| OSS | Open Sky System (Audi) |
| OSS | Optical Storage System |
| OSS | Optical Sight System |
| OSS | Ogrenci Secme Sinavi (Turkish university exam) |
| OSS | Observatory of the Sahara and the Sahel |
| OSS | Oncology Support Services (cancer) |
| OSS | Old School Soldiers |
| OSS | Offerings for Service (computer services) |
| OSS | Output Shaft Speed Sensor (automotive) |
| OSS | Order of the Sacred Sword (gaming) |
| OSS | Operational Storage Site |
| OSS | Office of Space Station (NASA) |
| OSS | Office of Statistical Standards |
| OSS | Optical Surveillance System |
| OSS | Ocean Surveillance System |
| OSS | Open Simulation System |
| OSS | Old Soft Shoe |
| OSS | Output Sub System |
| OSS | Off Site Sales |
| OSS | Open System Solution |
| OSS | Optics Support Structure |
| OSS | Office of Space Systems |
| OSS | Online Schedule System |
| OSS | Advanced Broadband Operational Support Systems |
| OSS | Overall System Sensitivity (radar) |
| OSS | Object Service Standard (SEMI) |
| OSS | Occupant Sensing System |
| OSS | Over Speed Sensor (railroad industry) |
| OSS | Optimizing SubSystem |
| OSS | Operation Safer Streets (police task force) |
| OSS | Objective Supply System |
| OSS | Office of Systems Support |
| OSS | On-Board Support Software |
| OSS | Ordinary Strength Steel |
| OSS | Oxenford State School (Gold Coast, Australia) |
| OSS | Operational Support Summary |
| OSS | Organizational Supply Support |
| OSS | Ocean State Soccer School (North Kingstown, RI) |
| OSS | Ormeau State School (Gold Coast, Australia) |
| OSS | Oh Shoot Situation (polite form) |
| OSS | Office of Special Security |
| OSS | Oifig Schrúdóir na Scannán (Film Censor's Office, Ireland) |
| OSS | Office for Special Support (academic support for students with special needs) |
| OSS | Operator Seat Switch |
| OSS | Operational Services Switch |
| OSS | Overt Surveillance System |
| OSS | Out-of-School Service (various locations) |