Manuel Alegre de Melo Duarte (born 12 May 1936) is a renowned Portuguese poet and politician. He is known for his opposition to the Salazarist regime and was exiled in Algeria during the dictatorship. As a prominent member of the Portuguese Socialist Party, which he helped found, Alegre has served as a deputy in the Assembleia da República.

In 2004, he challenged José Sócrates in the party's primaries for the position of Secretary-General, though was defeated by Sócrates, who later became the Prime Minister of Portugal. Alegre studied law at the University of Coimbra, where he was active in political, cultural, and sports activities.

His military service during the Portuguese Colonial War took place on the Angolan front, and he was imprisoned by the PIDE, the regime's political police, for his open opposition to the war. Alongside his political career, Alegre has produced an extensive literary oeuvre, gaining recognition in both academic and popular circles, particularly for his poetry.

Among his numerous literary honors are the Pessoa Prize in 1999 and the Camões Prize in 2017. He joined the Lisbon Academy of Sciences as an academician in 2005. Alegre also won the first prize at the RTP Song Festival with his poem "Uma flor de verde pinho", which was set to music by José Niza and performed by Carlos do Carmo.

In September 2005, he announced his candidacy for the 2006 Portuguese presidential elections, where he secured 20.72% of the vote, surpassing the official candidate from his party, Mário Soares, but did not prevent Cavaco Silva's first-round victory. Following the elections, he formed a civic movement called the Movement for Intervention and Citizenship.