São Mateus is a municipality located in the Brazilian state of Espírito Santo. Its population was estimated at 132,642 in 2020, and its area is 2,346 km². São Mateus is located at 36 meters above sea level. It is the second oldest and seventh most populous municipality in the state of Espírito Santo, Brazil. São Mateus was founded on 21 of September 1544, receiving municipal autonomy only in 1764.