The Monastery of Dumio (sometimes Dumium or Dumio, in Portuguese São Martinho de Dume), is a former paleo-Christian monastery in the civil parish of Dume, municipality of Braga, in northwestern Portugal. Originally a Roman villa, it was the base of a basilica by Suebi tribes, and later Christian monastery headed by Martin of Braga in the 6th century (c. 550–560). The re-discovery of the Roman ruins in the late 20th century resulted in archaeological excavations that unearthen its former use.