YSI
| Acronym | Definition |
|---|---|
| YSI | Yousendit (File Transfer Website) |
| YSI | Young Sustainable Impact (Norway) |
| YSI | Youth Service, Inc. (Philadelphia, PA) |
| YSI | Yellow Springs Instruments (Yellow Springs, OH) |
| YSI | You Said It |
| YSI | Young Social Innovators (Ireland) |
| YSI | Youth Science Institute |
| YSI | Young Scots for Independence (Edinburgh, Scotland, UK) |
| YSI | Youth Sports Institute (various locations) |
| YSI | You Stupid Idiot |