| Type: | Bishop |
| Honorific-Prefix: | Most Reverend |
| Martín Sarmiento de Osacastro | |
| Bishop of Tlaxcala | |
| Church: | Catholic Church |
| Diocese: | Diocese of Tlaxcala |
| Term: | 1548–1557 |
| Predecessor: | Pablo Gil de Talavera |
| Successor: | Fernando de Villagómez |
| Consecration: | 7 Apr 1549 |
| Consecrated By: | Juan Lopez de Zárate |
| Death Date: | 19 Oct 1557 |
| Death Place: | Puebla de los Angeles, México |
Martín Sarmiento de Osacastro, O.F.M. (died 1557) was a Roman Catholic prelate who served as Bishop of Tlaxcala (1548–1557).[1] [2]
Martín Sarmiento de Osacastro was appointed a priest in the Order of Friars Minor.
On 13 Jun 1548, he was appointed during the papacy of Pope Paul III as Bishop of Tlaxcala, and was accordingly consecrated on 7 Apr 1549 by Juan Lopez de Zárate, Bishop of Antequera.
He was the principal consecrator of Pedro Gómez Malaver, Bishop of Guadalajara (1550). In 1555, he attended the First Mexican Provincial Council.[3]
Osacastro died on 19 Oct 1557.