Luís Marques Guedes (born 25 August 1957) is a Portuguese lawyer and politician. He was Secretary of State for the Presidency of the Council of Ministers of the government of Pedro Passos Coelho, Secretary of State to the Prime Minister of Portugal, and the Government XII Undersecretary of State Assistant to the Prime Minister. He held the position of Chairman of the Parliamentary Group of the Social Democratic Party, of which he has been a member since 1995. When he ceased his activities as Minister of the Presidency, in late 2015, he became President of the Parliamentary Commission on Ethics, a section of the First Commission on Fundamental Rights.