| Acronym | Definition |
|---|
| FSN | Federal Stock Number |
| FSN | Fonds Spécial du Nigéria (French: Nigeria Trust Fund) |
| FSN | Family Support Network |
| FSN | Fonds National pour la Société Numérique (French: National Fund for the Digital Society) |
| FSN | Fox Sports Network |
| FSN | Food Safety Network (University of Guelph) |
| FSN | Factory Serial Number (manufacturing tracking number) |
| FSN | Fondo Sanitario Nazionale (Italian: National Health Fund) |
| FSN | Free Sites Network |
| FSN | File System Network |
| FSN | Fail Safe Network |
| FSN | Forward Sequence Number |
| FSN | Foreign Service National |
| FSN | Financial Sense Newshour (radio show) |
| FSN | Full Service Network |
| FSN | Fate/Stay Night (visual novel) |
| FSN | Fédération Suisse de Natation (French: Swiss Swimming Federation) |
| FSN | Financial Safety Net |
| FSN | Federatie Sloeproeien Nederland (Dutch rowing federation) |
| FSN | Fédération Suisse des Notaires (French: Swiss Federation of Notaries) |
| FSN | Forward Sequence Number (SS7 MTP Layer 2) |
| FSN | Food Service Network (Japan) |
| FSN | Frontul Salvarii Nationale (Romanian: National Rescue Front) |
| FSN | Free Sites Network (domain registrar) |
| FSN | Filter Smoke Number (engine test) |
| FSN | Ford Supplier Network |
| FSN | Fiscal Station Number |
| FSN | Fiber Security Network |
| FSN | Freedom Song Network (San Francisco, CA) |
| FSN | French-Speaking Nation |
| FSN | File Serial Number |