Battle of Pavón, (Sept. 17, 1861), in Argentine history, military clash at Pavón in Sante Fe province between the forces of the Argentine Confederation, commanded by Justo José de Urquiza, and those of Buenos Aires province, led by the governor, Bartolomé Mitre. Mitre’s victory there marked the end of decades of internal armed conflict in Argentina.

Following the defeat of Mitre’s Buenos Aires army at the Battle of Cepeda in 1859, Buenos Aires was constrained to join the confederation. But Mitre’s forces won in a subsequent confrontation at Pavón, though not decisively, and Urquiza concluded that he now had little chance of success in his bid for national leadership. Thus a new national government was set up, with the capital again at Buenos Aires (it had been moved to Paraná, in Entre Ríos province, in 1853, when Buenos Aires had seceded from the confederation), and Mitre became provisional president. When the congress that was elected under the new government convened in May 1862, Mitre was chosen president for a six-year term.