SIIL
| Acronym | Definition |
|---|---|
| SIIL | Sterlite Industries India Ltd. (Tamil Nadu, India) |
| SIIL | Sponge Iron India Limited (Hyderabad, Andhra Pradesh, India) |
| SIIL | Serum Institute of India Ltd. (est. 1966; Pune, Maharashtra, India) |
| SIIL | Siilinjärvi (Finnish) |
| SIIL | Sostegno Integrato Inserimento Lavorativo (Italian: Inclusion Support Integrated Working; disabled workers) |
| SIIL | Semantic Information Integration Laboratory (Khon Kaen University; Thailand) |