Juan de Ayolas (died c. 1537) was aconquistador born inBriviesca who explored the watershed of theRío de la Plata for theSpanish Crown. He accompaniedPedro de Mendoza on his 1534 expedition to colonize the region between the Río de la Plata and theStrait of Magellan and briefly succeeded him as the second governor of the region after Mendoza returned home in 1537.

Seeking supplies, he sailed up theParaná River and founded a fort called Corpus Christi, asSebastian Cabot had before him. LeavingDomingo Martínez de Irala at Puerto la Candelaria (modernFuerte Olimpo), he sailed up theParaguay River seeking a connection toPeru. He fought with theGuaraní, crossed theChaco to theAndes, and seized some loot there, but when he returned, he was killed with every man of his company by thePayagua.

The city ofAyolas in Paraguay, and itsairport (IATA: AYO; ICAO: SGAY) are named for him.

• Juan Abalos de Mendoza
• Gonzalo Casco
• Martín Suárez de Toledo
• Nicolás Colman
• Ulrich Schmidl

• Britannica Online Encyclopedia
• Chisholm, Hugh, ed. (1911)."Argentina" .Encyclopædia Britannica. Vol. 2 (11th ed.). Cambridge University Press. p. 468.
• MAURA, Juan Francisco.Alvar Núñez Cabeza de Vaca: el gran burlador de América. Parnaseo/Lemir. Valencia: Universidad de Valencia, 2008.

• Spanish conquistadors
• Explorers of Argentina
• Spanish explorers of South America
• 15th-century births
• 1537 deaths
• People from the Province of Burgos
• Castilian conquistadors
• 16th-century Spanish explorers

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• Short description matches Wikidata
• Pages where birth or death is being automatically determined
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• Wikipedia articles incorporating a citation from the 1911 Encyclopaedia Britannica with Wikisource reference
• Year of birth unknown