| Nicolasa Valdés | |
| Office: | First Lady of Chile |
| Term Label: | In role |
| Term Start: | July 16, 1810 |
| Term End: | September 18, 1810 |
| Successor: | Mercedes Fontecilla |
| President: | Mateo de Toro Zambrano |
| Birth Name: | María Nicolasa de Valdés y de la Carrera |
| Birth Date: | 7 January 1733 |
| Death Place: | Santiago, Captaincy General of Chile |
| Spouse: | Mateo de Toro Zambrano |
| Children: | 10 |
| Parents: | Domingo de Valdés y González de Soberal Ana Francisca de Borja de la Carrera y Ureta |
María Nicolasa de Valdés y de la Carrera, Countess of La Conquista (January 7, 1733 – December 18, 1810) was the inaugural First Lady of Chile from September 18, 1810, when her husband assumed the presidency in Chile's First Government Junta, until her death four months later.
Nicolasa Valdés was of Basque descent,[1] born in Santiago, the second daughter of Domingo de Valdés y González de Soberal and of Ana Francisca de Borja de la Carrera y Ureta. She married Mateo de Toro Zambrano, 1st Count of la Conquista on May 3, 1751, and together they had ten children. She died in Santiago, shortly before her husband, at the age of 77.
. José Toribio Medina . Diccionario Biográfico Colonial de Chile . 1906 . Imprenta Elziviriana . Santiago, Chile . Spanish . 869–870 .