Margarita Belén is a town in Chaco Province, in northeastern Argentina. It serves as the head town of the Primero de Mayo Department.
The settlement lies within the Chaco region, a lowland area of northern Argentina known for its subtropical climate and its history of cotton and cattle production. As a departmental seat, Margarita Belén functions as a local administrative center for the surrounding rural area.
It is distinct from other places bearing the name Margarita, including the well-known Caribbean island of Margarita off the coast of Venezuela.