SY
| Acronym | Definition |
|---|---|
| SY | System |
| SY | Syria |
| SY | School Year |
| SY | Sonic Youth (band) |
| SY | Shrewsbury (postcode, United Kingdom) |
| SY | South Yorkshire |
| SY | Sailing Yacht |
| SY | Syphilis |
| SY | Shipyard |
| SY | North Bay (Ontario Northland Railway Code) |
| SY | Scotland Yard |
| SY | Square Yard |
| SY | Screw You |
| SY | Switch Yard |
| SY | Staff Year |
| SY | See You/Ya |
| SY | Shoulder Yaw (robotics) |
| SY | Short-Yearlings |
| SY | Strudwick & Young Ltd. |