António José Serzedelo Silva Marques (Lisbon, 15 May 1945) is a Portuguese human rights activist, radio broadcaster, actor and a scholar. He is the oldest live LGBTI activist in Portugal (since May 1974). He was the author of the 1st LBGTI Manifesto in Portugal, "Freedom for the Sexual Minorities". He is the founder of , of which he is also currently president . He also founded and hosts a radio programme called (Alternative Lives).