| Mariana Fernández de Córdoba y Ayala | |
| Full Name: | Maria Fernandez de Cordoba and Ayala, fourth Lady of Casarrubios del Monte. |
| Birth Date: | c. 1394 |
| Death Date: | 1431 |
| Spouse: | Fadrique Enríquez de Mendoza |
| Issue: | Juana Enríquez Queen consort of Aragon |
| Noble Family: | Ayala |
| Father: | Diego Fernández de Córdoba y Carrillo, first Lord of Baena |
| Mother: | Inés de Ayala y Toledo |
Mariana Fernández de Córdoba y Ayala ([1] – 1431), also known as Mariana de Ayala Córdoba y Toledo, was the fourth Lady of Casarrubios del Monte in the province of Toledo. She was the daughter of Diego Fernández de Córdoba y Carrillo, first Lord of Baena, and Inés Ayala y Toledo, third Lady of Casarrubios del Monte.
Mariana married Fadrique Enríquez de Mendoza, Admiral of Castile and Lord of Medina de Rioseco around July 1425.[2] They had one daughter, Juana Enríquez (1425–1468), who married John II of Aragon.