Joseph Cassani (also spelt Casani, 26 November 1673 – 1750) was a Spanish Catholic historian.

Cassani was born in Madrid in 1673, entered the Society of Jesus on 16 November 1686, was still in active service of priestly functions in 1745, and died in 1750. He was one of the founders of the Academia de la Lengua española (Academy of the Spanish Language) at Madrid, and published a Diccionario de la Lengua Catellana (Catalan dictionary) there in 1726–1730, in six volumes. He was a very prolific writer. Among his works may be noted Admirable vida, singulares virtudes etc. del extçtico Varon P. Dionisio Rickel (Madrid, 1738), and Varones ilustres de la Compañia de Jesus Escual militar de fortificacion Tratado de la naturaleza y orígen de los cometas (Madrid, 1737).

He was a member of the Academia from 6 July 1713. Although he never visited America, he appealed particularly to Americans through his Historia de la Provincia de la Compañia de Jesus del Nueva Reyno de Granada en la América (Madrid, 1741), the only regular chronicle of the Jesuit Order in Colombia thus far extant. (Note: Cassani wrote the "Historia" in Venezuela.) The fact that Cassani was never in the New World detracts somewhat from the usefulness of this otherwise valuable history, as far as ethnologic and ethnographic data are concerned; but it does include data on the missions in the upper Orinoco basin. The work is exceedingly rare.

•  This article incorporates text from a publication now in the public domain: Herbermann, Charles, ed. (1913). "Joseph Cassani". Catholic Encyclopedia. New York: Robert Appleton Company.
• Sommervogel-de Backer, Bibl. des éscriv. de la c. de J.
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