SYD
| Acronym | Definition |
|---|---|
| SYD | Seitokai Yakuindomo (manga and anime) |
| SYD | Sum-of-Years Digits |
| SYD | Sum-Of-The-Years'-Digits (depreciation method; also seen as SOYD) |
| SYD | Series Yaw Dampner (aviation) |
| SYD | Stonewall Young Democrats (est. 2004; West Hollywood, CA) |
| SYD | System Drawings |
| SYD | Subject Your Discretion (air traffic control) |
| SYD | Simply Your Driver (vehicle service) |
| SYD | Slay Your Dragon |
| SYD | Sydney, New South Wales, Australia - Sydney Municipal (Airport Code) |