Santa Fe Province, Argentina in the context of Santa Fe, Argentina

The Pampas (/ˈpæmpəz/; from Quechua pampa 'plain'), also known as the Pampas Plain, are fertile South American low grasslands that cover more than 1,200,000 square kilometres (460,000 sq mi) and include the Argentine provinces of Buenos Aires, La Pampa, Santa Fe, Entre Ríos, and Córdoba; all of Uruguay; and Brazil's southernmost state, Rio Grande do Sul. The vast plains are a natural region, interrupted only by the low Ventana and Tandil hills, near Bahía Blanca and Tandil (Argentina), with a height of 1,300 m (4,265 ft) and 500 m (1,640 ft), respectively. This ecoregion has been changed by humans, especially since the release of animals like cattle, pigs, and especially sheep onto these plains.

The climate is temperate, with precipitation of 600 to 1,200 mm (23.6 to 47.2 in) that is more or less evenly distributed throughout the year, making the soils appropriate for agriculture. The area is also one of the distinct physiography provinces of the larger Paraná–Paraguay plain division.

The Federal Pact (Spanish: Pacto Federal) was a treaty first signed by the Argentine provinces of Buenos Aires, Entre Ríos and Santa Fe on 4 January 1831, for which a Federal military alliance was created to confront the Unitarian League. Other provinces would later join the treaty.