Antonio Pedro Sancho Dávila y Osorio (or Álvarez Osorio y Gómez Dávila), X Marquess of Astorga, (c. 1615 - Madrid, 27 February 1689) was a Spanish noble, military, politician and diplomat.

He was the eldest son of Antonio Sancho Davila, Marquis of Velada, Governor of the Duchy of Milan, and Constanza Osorio, daughter of Pedro Álvarez Osorio, IX Marquess of Astorga. Besides Marquess of Astorga, he was also IV Marquess of Velada and III of la Villa de San Román, IX Count of Trastámara and XI of Santa Marta, Lord of the House of Villalobos and twice Grandee of Spain.^[1]

Throughout his life he was a gentleman of the chamber of Felipe IV and Carlos II, captain of the Spanish army during the Catalan Revolt, and Governor of the North African cities of Oran and Mazalquivir (1652-1660). In 1662, he was appointed Viceroy of Navarre and in 1664 Viceroy of Valencia.^[2]

In 1667, he became Ambassador of Spain to the Holy See, where he influenced the conclaves which chose Popes Clement IX (1667) and Clement X (1670). For this he was awarded with the Viceroyalty of Naples (1672-1675). After his return, he became Councilor of State and Majordomo of Queen Marie Louise d'Orléans.^[2]
Astorga carried out his responsibility as Majordomo of the Queen until her death, which occurred on 12 February 1689.
Astorga survived his Queen for barely two weeks, as he died in Madrid on the 27th of the same month.^[2]

Dávila married three times :

• in 1634 with his niece Juana María de Velasco y Osorio, Marchioness of Salinas de Río Pisuerga. Died in October 1634 from typhus.
• Ana María de Guzmán y Silva, Countess of Saltés. Died in 1637.
• María Pimentel, daughter of the Juan Francisco Pimentel, 7th Duke of Benavente.

He had no children from the three marriages, so his noble titles passed to his sister Ana, the only survivor of his siblings at the time of his death.^[2]