Philip O'Sullivan Beare (Irish: Pilib Ó Súilleabháin Béirre, c. 1590 – Spain, 1660) was an Irish soldier who became more famous as a writer.
He was son of Dermot O'Sullivan and nephew of Donal O'Sullivan Beare, Prince of Beare. The O'Sullivans, headed by the O'Sullivan Beare, owned much of Valentia Island in south-western Ireland.
He was sent to Spain in 1602, and was educated at Compostela by Vendamma, a Spaniard, and John Synnott, an Irish Jesuit.
He served in the Spanish army. In 1621 he published his Catholic History of Ireland, a work not always reliable, but valuable for the Irish wars of the author's own day. He also wrote a Life of St. Patrick, a confutation of Gerald of Wales and a reply to James Usher's attack on his History.
This article incorporates text from a publication now in the public domain: Herbermann, Charles, ed. (1913). "". Catholic Encyclopedia. New York: Robert Appleton.