The Battle of Tacuarí was a battle in Southern Paraguay between revolutionary forces under the command of General Manuel Belgrano, member of the Primera Junta government of Argentina, and Paraguayan troops under colonel Manuel Atanasio Cabañas, at the time at the service of the royalists.

Manuel José Joaquín del Corazón de Jesús Belgrano y González, usually referred to as Manuel Belgrano, was an Argentine public servant, economist, lawyer, politician, journalist, and military leader. He took part in the Argentine Wars of Independence and designed what became the flag of Argentina. Argentines regard him as one of the main Founding Fathers of the country.