| GISS | Gan Imtermate Secondary School 
| Others |
| GISS | General Impression of Size and Shape
| Others |
| GISS | General Impression Size And Shape
| Others |
| GISS | Generic Impact Scoring System
| Others |
| GISS | Generic Internet Service Specification
| Others |
| GISS | Geographic Information Science and Systems
| Others |
| GISS | Geographic Information System Specialist
| Others |
| GISS | Geographic Information Systems Specialist
| Others |
| GISS | Georgian Institute for Strategic Studies
| Others |
| GISS | German International School Sydney
| Others |
| GISS | Give Invest Save Spend
| Others |
| GISS | Global Information Security Survey
| Others |
| GISS | Global Investment Strategies Systems
| Others |
| GISS | Global Issues Service Summit
| Others |
| GISS | Global It Security Summit
| Others |
| GISS | Goddard Institute For Space Science
| Others |
| GISS | Goddard Institute for Space Studies
| Others |
| GISS | Goddard Institute of Space Studies
| Others |
| GISS | Gordonstoun International Summer School
| Others |
| GISS | Governance Institute for Student Success
| Others |
| GISS | Greater IPAC Science Symposium
| Others |
| GISS | Gulf Islands Secondary School
| Others |