Odemira is a town and a municipality in Beja District in the Portuguese region of Alentejo. The population in 2021 was 29,538, in an area of …Odemira is a town and a municipality in Beja District in the Portuguese region of Alentejo. The population in 2021 was 29,538, in an area of 1,720.6 square kilometres, making it the largest municipality of Portugal by area, but one of the least densely populated.