Quinta do Lago was founded in 1971 by Polish-Brazilian property developer André Jordan, three years after the end of Salazar's rule.

The original 550-hectare site, "Quinta dos Ramalhos" (Ramalhos Estate), contained the ruins of an old farmhouse (today "Casa Velha", having been rebuilt as a restaurant in 1972), a stone pine forest adjacent to both the Ria Formosa and the growing resort of Vale do Lobo which had been founded eight years earlier.

The Pinto de Magalhães family previously owned the large beach-lined estate for over 300 years.

In 1974, revolutionary leader Otelo Saraiva de Carvalho presided over the golf courses' inauguration; in 1976, the Portuguese Open was held in Quinta do Lago for the first time.

In 1987, Jordan sold the resort (i.e. Planal, the holding company) to a consortium of British shareholders headed by Roger Abraham, a former banker at Chase Manhattan Bank, and food entrepreneur David Thompson.