Mário Sérgio Quaresma Gonçalves Marques (born 25 February 1957) is a Portuguese lawyer and politician, who served as member of the Assembly of the Republic.

He was also a member of the European Parliament for the PPD/PSD from 1999 to 2009, when he refused to reinstate the lists due to disagreement with the then chairman of the PPD/PSD-Madeira Political Commission and president of the Regional Government of Madeira, Alberto João Jardim.

In the European Parliament, he was a member of the Group of the European People's Party (Christian Democrat) and European Democrats, of the Committee on Regional Development, alternate member of the Committee on Economic and Monetary Affairs, Vice-President of the Delegation for relations with South Africa, Coordinator of the Informal Group on the Outermost Regions and alternate member of the delegation for relations with the Andean Community.

[2] As a motto he proposed a 'Trust Pact' based on the reform of the political system, one of the five pillars of his electoral program.

[3] Among its most emblematic proposals are the preferential vote, the referendum to revoke political office, the opening of party elections for supporters and the re-establishment of the maritime connection between Madeira and mainland Portugal.