The Tambre is a coastal river that crosses Galicia, in northwestern Spain. Its basin covers 1,531 square kilometres (591 sq mi).

The river flows through the province of A Coruña; the municipalities along its course are Sobrado, Curtis, Vilasantar, Boimorto, Mesía, Frades, Arzúa, O Pino, Oroso, Ordes, Trazo, Tordoia, Santiago de Compostela, Val do Dubra, Ames, A Baña, Brion, Negreira, Outes, Mazaricos, Noia and Lousame. Its mouth forms the Ría de Muros e Noia estuary.

It has been designated a Site of Community Importance.

In ancient times it was called Támaris, its name being related to that of the River Tamar in Cornwall. It was from the lands north of this river that the Spanish County of Trastámara and the royal House of Trastámara derive their name (Tras-Támara meaning "across the Tambre"). Tamarix may derived its name from the river.

• 
  Ría de Muros e Noia
• 
  Ponte Maceira bridge
• 
  Ponte Nafonso bridge

• List of rivers of Spain
• Rivers of Galicia

42°49′42″N 8°52′23″W / 42.8282°N 8.8730°W / 42.8282; -8.8730