Manuel Alegre de Melo Duarte (Águeda, May 12, 1936) is a Portuguese poet and politician, an opponent of the Salazarist Regime.

He was in exile in Algeria during the dictatorship. He is a prominent member of the Portuguese Socialist Party, the party of which he was founder and vice-president and for which he is a deputy in the Assembleia da República. In 2004 he faced José Sócrates in the party's primaries for the post of Secretary General, losing to the later Portuguese Prime Minister.

He studied Law at the University of Coimbra. From very early on he demonstrated his political ideals. He completed his military service in the Portuguese Colonial War on the Angolan front. At that time he was arrested by the PIDE, the political police of the Regime, for openly opposing the war. Parallel to his political career, he has produced a great literary work that has given him notoriety in both academic and popular circles. He highlights above all his poetic work.

He received numerous literary prizes, including the Premio Pessoa in 1999. In 2005 he became an academic at the Lisbon Academy of Sciences.

He also received the first prize at the RTP Song Festival, with his poem Uma flor de verde pinho, which was turned into a song by José Niza and performed by Carlos do Carmo.

In September 2005, he announced his candidacy for the 2006 Portuguese presidential elections that took place on January 22, 2006. Alegre obtained 20.72% of the vote, failing to avoid Cavaco Silva's victory in the first round but getting a result superior to the official candidate of his party, Mário Soares.

After the elections, he formed a civic movement called the Movement for Intervention and Citizenship.