| ISTS | I Shot the Sheriff. 
| Others |
| ISTS | Information Security Talent Search
| Others |
| ISTS | Initiative on Science and Technology for Sustainability
| Others |
| ISTS | Institute for Security Technology and Society
| Others |
| ISTS | Integrated Software Training Solutions
| Others |
| ISTS | Intel Science Talent Search
| Others |
| ISTS | Inter-State Transmission System
| Others |
| ISTS | International Scholarship and Tuition Services
| Others |
| ISTS | International Sea Turtle Society
| Others |
| ISTS | International Society for Twin
| Others |
| ISTS | International Society for Twin Studies
| Others |
| ISTS | International Speech Test Signal
| Others |
| ISTS | International Styling and Tuning Show
| Others |
| ISTS | International Switched Transit Service
| Others |
| ISTS | Ion Source Test Stand
| Others |
| ISTS | Iowa Science Teachers Section
| Others |
| ISTS | Iowa Science Teaching Section
| Others |