| Acronym | Meaning |
| SSJ | Sector San Juan (US Coast Guard) |
| SSJ | Self-Screening Jammer |
| SSJ | Service de Santé de la Jeunesse (French: Youth Health Service; Switzerland) |
| SSJ | Single Sideband Jammer |
| SSJ | Sole-Source Justification |
| SSJ | Stranka Srpskog Jedinstva (Party of Serb Unity, Serbia and Montenegro) |
| SSJ | Sukhoi Super Jet |