Balsas (Portuguese pronunciation: [ˈbawsɐs]) is a city in the state of Maranhão, northeast Brazil.

It is located in southern Maranhão, 800 km from the capital of the state, São Luís.

Balsas covers an area of 13,141.64 km2, being the largest municipality in Maranhão.

There are many streams and rivers in the municipality, but the most important is Rio Balsas, which crosses the city.

The infant mortality rate is 35.1 deaths /1,000 live births and life expectancy is 64.1 years.