← 1865 1864 1863 1866 in Paraguay → 1867 1868 1869
Decades:	1840s 1850s 1860s 1870s 1880s
See also:	Other events of 1866 Timeline of Paraguayan history

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

Births

Deaths

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