Diego Osorio de Escobar y Llamas (c. 1608, Coruña, Galicia, Spain – October 17, 1673, Puebla, New Spain) was Roman Catholic bishop of Puebla (1656–73) and viceroy of New Spain from June 29, 1664 to October 15, 1664.
Osorio de Escobar y Llamas held the offices of canon, inquisitor and vicar-general in the diocese of Toledo. He was a member of the secular clergy, but a friend of the Jesuits. On 2 Aug 1655, he was chosen during the papacy of Pope Alexander VII as bishop of Puebla, on the recommendation of Cardinal Moscoso. On 25 Jul 1656, he was consecrated bishop.
He took up the position in 1656 and remained there until his death in 1673. There he built the convent of La Santísima Trinidad, hastened the construction of the cathedral, and paid for the chapel and altar of Nuestra Señora de Guadalupe. In 1663 he was named archbishop of Mexico City, but he declined the office in order to remain in Puebla (although he did administer the diocese for a few months until the arrival of the new archbishop, Alonso de Cuevas Dávalos). While bishop, he was the principal consecrator of: Luís de Cifuentes y Sotomayor, Bishop of Yucatán (1660); Juan de Sancto Mathía Sáenz de Mañozca y Murillo, Bishop of Santiago de Cuba (1662); and Juan de la Torre y Castro, Bishop of Nicaragua (1662).
He was viceroy for less than four months, from June to October 1664. He was named to the position to replace Viceroy Juan de Leyva de la Cerda, who was ordered back to Spain because of corruption. Osorio apparently accepted the position with reluctance. He was a stranger to profane affairs, and resigned as viceroy at the first opportunity in order to return to his diocese in Puebla.