| Acronym | Definition |
|---|
| SIFF | Seattle International Film Festival |
| SIFF | Save Indian Family Foundation (India) |
| SIFF | Sedona International Film Festival (Sedona, AZ) |
| SIFF | Shanghai International Film Festival (China) |
| SIFF | Solomon Islands Football Federation |
| SIFF | Sims International Film Festival (Simatography) |
| SIFF | Stateless Internet Flow Filter |
| SIFF | Singapore International Film Festival (est. 1986) |
| SIFF | Sydney International Film Festival (Sydney, Australia) |
| SIFF | Survival International Film Festival (Australia) |
| SIFF | Swiss International Finance Forum |
| SIFF | Successor Identification Friend or Foe |
| SIFF | Salento International Film Festival (Italy) |
| SIFF | Social Investment Forum Foundation (environmental group) |