Marechal Deodoro is a municipality and an important tourist center of Alagoas, Brazil. Its population is 52,380 (2020) and its area is . The town was the first capital of Alagoas state.
The city was founded as Vila Madalena in 1611, and features a number of historical buildings from the colonial period. It was also referred to as Alagoas, or the City of Alagoas. The first president of the Republic of Brazil, Marshal () Deodoro da Fonseca, was born in Vila Madalena; the city was later renamed in his honour.