Odescalchi, a noble Italian family, originally from Como. - Maec' Axtoxio, born in Como about 1620, was a cousin of Pope Innocent XI. (Benedetto Odescalchi). He entered the priesthood, and after his cousin's promotion to a cardinalate went to Rome to reside; but he refused all honors and preferments, and devoted himself to Avorks of charity. In 1656 he turned his house into a hospital, and received there the poor and the destitute of all nations. He subsequently bought some adjacent houses, and enlarged his hospital, until it contained 1,000 beds. At his death in 1670 he bequeathed all his property to it, and Innocent XI. not long afterward enlarged it to the capacity of 3,000 beds. It is now known as the hospital of St. Gall. - Tommaso, a kinsman of the preceding, died in 1692. He was appointed almoner of Innocent XI., and determined to erect an asylum for children. He began with 38, and through the liberality of the pope the number was soon increased to 70. In 1686 he laid in the Trastevere the foundation of a large hospital, which he named San Michele, to be occupied solely by vagrant boys, who were to be educated and taught the weaver's trade.

At his death he left considerable funds for its further endowment; and its scope and objects have since been largely extended. - The character of the family seems not to have been changed by the lapse of years, for in 1810 an industrial school for poor girls was founded at Rome by Carlo Odescalciii, who was cardinal vicar under Gregory XVI, abdicated his rank and became a Jesuit in 1842, and died in 1848. - Another distinguished member of this family was Baltassake Odescalciii, duke of Ceri, who was born in Rome in 1748, and died there in 1810. He was a great patron of learning, founded in his house the accademia degli occult/, and published a volume of poetry and Istoria dell' accademia de' Lincei (Rome, 1806). - The present prince Baltassake III. (born in 1841) is a devoted partisan of Garibaldi.