Estanislao José Antonio Lynch y Roo, was an Argentine naval officer and wealthy national, the brother of the famous landowner of the "Rio de la Plata" captain Patricio Lynch and the grandson of an Irish immigrant, Patrick Lynch. Estanislao was the third son of Justo Pastor Lynch (1755–1830) and Ana Bernardo Roo (d.1836).

During his period as an Officer in the Argentine Army of the Andes protected his territory and liberated from the Spanish Crown, On 2 January 1817 the Buenos Aires city council appointed Estanislao Lynch as the major of Barracas.

Along with Chilean exiles and the Army of the Andes, he crossed the Andes to help liberate Chile.

Eventually, he retired from the army and expanded the family's businesses to Valparaiso where he settled and married Carmen Solo de Zaldívar y Rivero, a lady from the Chilean high-society, the couple settled in Chile and issued:

• Luis Alfredo Lynch, Naval Officer
• Patricio Lynch, appointed Chilean Ambassador to Spain, previously a Naval officer in the Chilean Navy reaching the rank of admiral.
• Julio Angel Lynch, Naval Officer

• Coghlan, Eduardo A., Los Irlandeses en la Argentina: Su Actuación y Descendencia (Buenos Aires, 1987), p. 626.
• Buenos Aires City Council, Archivo General de la Nación, Series IV, Vol. VII, Sections LXXIV to LXXIX, 1816 and 1817 (Buenos Aires, 1930).
• Dictionary of Irish Latin American Biography, by Gonzalo Cané