- Sengerema Informal Sector Centre
- SHDEPHA+ KAHAMA
- SHINYANGA FOUNDATIONFUND
- SHIRIKA LA KUPAMBANA NA UKIMWI MKOA WA MTWARA
- SHIRIKA LA MAENDELEO NA SERA TANDAHIMBA
- SHIRIKA LA WAKULIMA NA WAFUNGAJI LUMESULE
- SIHA DEVELOPMENT ORGANIZATION
- Social Awareness and Live Support (SALISU)
- Society for Service to Rural Development in Tanzania
- SOCIO-ECONOMIC DEVELOPMENT TRUST FUND