| SSO | Safety Signification Operation 
| Others |
| SSO | Sanitary Sewer Overflow
| Others |
| SSO | Sao Lourenco, Minas Gerais, Brazil
| Others |
| SSO | Satellite Switching Office
| Others |
| SSO | Satria Street Shoot Out
| Others |
| SSO | School Service Officer
| Others |
| SSO | School Services Officer
| Others |
| SSO | School Support Officer
| Others |
| SSO | Secondary Significant Other
| Others |
| SSO | Secret Supercar Owner
| Others |
| SSO | Semi Synthetic Oil
| Others |
| SSO | Senior Support Officer
| Others |
| SSO | Server Side Object
| Others |
| SSO | Shared Service Organization
| Others |
| SSO | Shared Storage Option
| Others |
| SSO | Shell Service Object
| Others |
| SSO | Ship Security Officer
| Others |
| SSO | Signal Security Office
| Others |
| SSO | Simultaneously Switching Outputs
| Others |
| SSO | Singapore Symphony Orchestra
| Others |
| SSO | Single Sign-On
| Others |
| SSO | Single Small Outline Package
| Others |
| SSO | Skate Society Of Oregon
| Others |
| SSO | Small String Optimisation
| Others |
| SSO | Society of Surgical Oncology
| Others |
| SSO | Software and Solutions Organization
| Others |
| SSO | Software Storage Object
| Others |
| SSO | Soldier Special Ops
| Others |
| SSO | Sortof Significant Other
| Others |
| SSO | Source Selecting Official
| Others |
| SSO | Source Selection Official
| Others |
| SSO | Space Shuttle Orbiter
| Others |
| SSO | SpaceShipOne
| Others |
| SSO | Special Security Office
| Others |
| SSO | Special Security Office(R)
| Others |
| SSO | Special Security Officer
| Others |
| SSO | Special Source Operations
| Others |
| SSO | Spot Security Office
| Others |
| SSO | Springfield Symphony Orchestra
| Others |
| SSO | State Services Organization
| Others |
| SSO | Stateful Switch Over
| Others |
| SSO | Storage System Operator
| Others |
| SSO | Struck Submerged Object
| Others |
| SSO | Student Services Office
| Others |
| SSO | Student State Officer
| Others |
| SSO | Subsystem Operation (in Spacelab)
| Others |
| SSO | Super Stock Alcohol
| Others |
| SSO | Super Stock Open
| Others |
| SSO | Super Street Oil
| Others |
| SSO | Super Street Outlaw
| Others |
| SSO | Superior Soap Opera
| Others |
| SSO | Support System for OEX
| Others |
| SSO | Survey Software Online
| Others |
| SSO | System Security Officer
| Others |
| SSO | System Staff Officer
| Others |