São Martinho Grande is a settlement located in the southern region of the island of Santiago in Cape Verde. It falls within the municipality of Ribeira Grande de Santiago and serves as a local residential area situated between major urban centers.
The settlement is positioned approximately 4 km east of Cidade Velha and 6.5 km west of the city centre of Praia. The national road EN1-ST05 passes to its north, while the small Atlantic bay of Calheta de São Martinho lies 1.5 km to the south. Historical records indicate that the area was identified as "Kalyete de S. Martin" on a map produced by Jacques-Nicolas Bellin in 1747.