1866 in Paraguay

Events in the year 1866 in Paraguay.

Incumbents

 * President: Francisco Solano López
 * Vice President: Domingo Francisco Sánchez

Events

 * January 31 - Battle of Pehuajó
 * May 2 - Paraguayan War: Battle of Estero Bellaco
 * May 24 - Battle of Tuyutí
 * July 18 - Battle of Boquerón (1866)
 * September 1–3 - Battle of Curuzú
 * September 22 - Battle of Curupayty

Deaths

 * July 18 - Elizardo Aquino, general, killed in action