| ISTC | Idaho State Tax Commission 
| Others |
| ISTC | Illinois Science Technology Coalition
| Others |
| ISTC | Illinois Sustainable Technology Center
| Others |
| ISTC | Illinois Sustainable Technology Center, University of Illinois
| Others |
| ISTC | Incunabula Short Title Catalogue
| Others |
| ISTC | Independent Sector Treatment Centre
| Others |
| ISTC | Information Society Technologies Committee
| Others |
| ISTC | Innovative Solutions and Technologies Center
| Others |
| ISTC | Institute of Scientific and Technical Communicators
| Others |
| ISTC | Integrated System Test Capability
| Others |
| ISTC | Intel Science and Technology Center
| Others |
| ISTC | Intel Science and Technology Centers
| Others |
| ISTC | Intel Science and Technology Centres
| Others |
| ISTC | Intel Science Technology Center
| Others |
| ISTC | International Scale Touring Car
| Others |
| ISTC | International Science and Technology Center
| Others |
| ISTC | International Snowboard Training Center
| Others |
| ISTC | International Space Training Center
| Others |
| ISTC | International Special Training Center
| Others |
| ISTC | International Sports Training Camp
| Others |
| ISTC | International Standard Text Code
| Others |
| ISTC | International Standards for Tuberculosis Care
| Others |
| ISTC | International Student Travel Confederation
| Others |
| ISTC | Interpersonal Skills Teaching Centre
| Others |
| ISTC | Iron and Steel Trades Confederation
| Others |
| ISTC | Italian Super Turismo Championship
| Others |