| Official Name: | São Martinho, Santa Catarina |
| Settlement Type: | Municipality |
| Pushpin Label Position: | bottom |
| Pushpin Map Caption: | Location in Brazil |
| Subdivision Type: | Country |
| Subdivision Name: |  Brazil |
| Subdivision Name1: | South |
| Subdivision Type2: | State |
| Subdivision Name2: | Santa Catarina |
| Subdivision Type3: | Mesoregion |
| Subdivision Name3: | Sul Catarinense |
| Unit Pref: | Imperial |
| Population As Of: | 2020 [1] |
| Population Total: | 3,171 |
| Timezone: | UTC -3 |
São Martinho is a municipality in the state of Santa Catarina in the Southern region of Brazil.[2] [3] [4] [5]
The municipality contains part of the Serra do Tabuleiro State Park, a protected area created in 1975.The lushly-forested park protects the sources of the Vargem do Braço, Cubatão and D'Una rivers, which supply most of the drinking water for greater Florianópolis and the south coast region.
Venerable Aloísio Sebastião Boeing was born there.