Mariana Victoria of Spain (31 March 1718 – 15 January 1781) was an Infanta of Spain by birth and was later the Queen of Portugal as wife of King Joseph I. The eldest daughter of Philip V of Spain and Elisabeth Farnese, she was engaged to the young Louis XV of France at the age of seven. Rejected due to her age, the marriage never took place and she was sent back to Spain. In 1729 she was married to the son of John V of Portugal. The mother of Maria I of Portugal she also acted as regent of Portugal during the last months of her husbands life and acted as advisor to her daughter in her reign. Before her husbands accession the the throne in 1750 she was known as the "Princess of Brazil".