Sebastião Phillipes Martins Estácio da Veiga (6 May 1828 in Tavira – 7 December 1891 in Lisbon), was a Portuguese archeologist and writer, known for having discovered several important archaeological sites in the Algarve and having made advancements in the study of several others also found in the region and in the Alentejo.

He studied at Faro's high-school, moving afterwards to Lisbon to study at the Escola Politécnica de Lisboa, following the career of secretary official of the Post-Office General Sub-Inspection of the Kingdom.

In 1876, after the strong rain season that occurred in the Algarve, the Fontes Pereira de Melo office charged him with the inventory of all archeological remnants that were to be discovered in the region (as in the case of the Roman Ruins of Milreu, the Roman fish processing plants in Praia da Luz and others found in the Alentejo).

In 1880, Estácio da Veiga hosted the International Congress of Anthropology and Pre-History Archeology, in Lisbon.

Estácio da Veiga had achieved the status of knight nobleman (fidalgo cavaleiro) of the Royal House, a title also earned by his father José Agostinho Estácio da Veiga.