| Acronym | Definition |
|---|
| NSIS | Next Steps in Signaling |
| NSIS | Null Soft Based Installer |
| NSIS | Nullsoft Scriptable Installer System |
| NSIS | Nuovo Sistema Informativo Sanitario (Italian: New Health Information System) |
| NSIS | Nullsoft Scriptable Install System |
| NSIS | No Such Interface Supported (computing) |
| NSIS | North Strabane Intermediate School (Pennsylvania) |
| NSIS | National Sheep Identification System (Ireland) |
| NSIS | Nullsoft SuperPimp Install System |
| NSIS | North Snohomish, Island and Skagit |
| NSIS | Nationaal Schengen Informatie Systeem (Dutch, Schengen area police computer system) |
| NSIS | New Student Information System |
| NSIS | National Security Investigation Section (Canada) |
| NSIS | North Shore Immigration Service Limited (New Zealand) |
| NSIS | Nordevald Software & Information Services |
| NSIS | NASA Software Information System |
| NSIS | North Sumter Intermediate School |