Mencía Calderón y Ocampo (1514 – c. 1564) was a Spanish noble lady, first expeditionary woman in the Río de la Plata.

She was married to Juan de Sanabria, a noble Spanish expeditionary who died shortly before leaving for New Spain.

[2] Through his mother, Mencía Calderón, was related to Francisco Pizarro and Hernán Cortés, belonging to noble Castilian families.

The fleet survived storms and attacks by French corsairs before managing to reach the isle of Santa Catalina.

Mencía took the rank of Adelantada upon herself and led an expedition of 21 women and 22 men across 1.600 km of rainforest, following the same path that years before had followed Alejo García and Alvar Núñez Cabeza de Vaca.