| Melchor Casco de Mendoza | |
| Order: | Alcalde (2nd vote) of |
| Office: | Buenos Aires |
| Term Start: | 1605 |
| Term End: | 1606 |
| Birth Date: | 1581 |
| Birth Place: | Asuncion, Paraguay |
| Death Date: | 1658 |
| Death Place: | Buenos Aires, Argentina |
| Birthname: | Melchor Casco de Mendoza y Valderrama |
| Occupation: | Politician |
| Profession: | Militia |
| Signature: | Melchor Casco de Mendoza firma.png |
| Branch: | Spanish Army |
| Rank: | Captain |
Melchor Casco de Mendoza (1581–1658) was a Spanish nobleman, alcalde and alferez real of Buenos Aires.[1] He also served as regidor of Asuncion in 1620.[2]
Melchor was born in Asuncion, the son of Víctor Casco de Mendoza and Lucía Valderrama, daughter of Juan de Fustes.[3] He was married to Catalina Astor, daughter of Pedro de Izarra Astor and Úrsula Gómez y Luyz.[4] Melchor Casco de Mendoza was grandson of Gonzalo Casco and María Mendoza, daughter of Gonzalo de Mendoza and Isabel Irala (daughter of Domingo Martínez de Irala).