Antonio Vitorino took part in the founding of the Union of the Left for Socialist Democracy (UEDS) in 1978. Elected as a Member of Parliament in 1980 on the list of the Republican and Socialist Front, he entered the Assembly of the Republic at the age of 23. He earned a law degree from the University of Lisbon in 1981 and became a university lecturer the following year.
Re-elected as a Member of Parliament in 1983, he was appointed at the age of 26 Secretary of State for Parliamentary Affairs in the government of Mário Soares. Elected in 1985, he became Chair of the Parliamentary Committee on Constitutional Affairs. In 1986, he served as Deputy Secretary to the Governor of Macao and obtained a master’s degree in law and political science. He returned to Parliament in 1987 and was elected Judge of the Constitutional Court in 1989 on the proposal of the Socialist Party.
He resigned in 1994 to run in the European elections, became a Member of the European Parliament, and assumed the chairmanship of the Committee on Civil Liberties. Re-elected as a national MP in 1995, he was appointed on 30 October Minister of the Presidency and Minister of National Defence in the government of António Guterres. In 1999, he became European Commissioner for Justice and Home Affairs.
A lawyer by profession, he has held senior positions in the private sector, served as President of the Res Publica Foundation, worked as a political commentator, and was President of the Jacques Delors Institute from 2010 to 2016. In June 2018, he was elected Director General of the International Organization for Migration (IOM).