Monsanto is a village and a former civil parish in the municipality of Idanha-a-Nova, Portugal. In 2013, the parish merged into the new parish Monsanto e Idanha-a-Velha. It covered an area of 131.76 km² and had 828 inhabitants (June 30 2011). It was the principal town of the concelho between 1174 and the beginning of the 19th century, and the county seat in the period of 1758-1853. In recent decades, Monsanto has become popularly known as "the most Portuguese village of Portugal" in a class of twelve classified historic villages in Portugal.