The Mariano Procópio Museum is an ecological museum located in Juiz de Fora, Minas Gerais, Brazil. Founded in 1915 by Alfredo Ferreira Lange, it is the first museum ever built in Minas Gerais, and only the third museum ever built in Brazil. The museum contains approximately 45,000 specimens.
The museum's architecture consists of two buildings: The Villa Ferreira Lage, constructed between 1856 and 1861, and an annex built in 1922 specifically for the museum. Both are currently closed for restoration.
The museum serves as an important collection of items of ecological interest, complete with large gardens and diverse examples of Brazilian flora.