Born at Penshurst Place, Kent, he was the eldest son of Sir Henry Sidney and Lady Mary Dudley. His mother was the daughter of John Dudley, 1st Duke of Northumberland, and the sister of Robert Dudley, 1st Earl of Leicester. His younger sister, Mary Sidney, married Henry Herbert, 2nd Earl of Pembroke. Mary Sidney, who upon her marriage became the Countess of Pembroke, was a writer, translator and literary patron. Sidney dedicated his longest work, the Arcadia, to her. After her brother's death, Mary Sidney Herbert reworked the Arcadia, now known as The Countess of Pembroke's Arcadia.

Philip was educated at Shrewsbury School and Christ Church, Oxford. In 1572, he travelled to France as part of the embassy to negotiate a marriage between Elizabeth I and the Duc D'Alençon. He spent the next several years in mainland Europe, moving through Germany, Italy, Poland, the Kingdom of Hungary and Austria. On these travels, he met a number of prominent European intellectuals and politicians.

Returning to England in 1575, Sidney met Penelope Devereux, the future Lady Rich; though much younger, she would inspire his famous sonnet sequence of the 1580s, Astrophel and Stella. Her father, the Earl of Essex, is said to have planned to marry his daughter to Sidney, but he died in 1576. In England, Sidney occupied himself with politics and art. He defended his father's administration of Ireland in a lengthy document. More seriously, he quarrelled with Edward de Vere, 17th Earl of Oxford, probably because of Sidney's opposition to the French marriage, which de Vere championed. In the aftermath of this episode, Sidney challenged de Vere to a duel, which Elizabeth forbade. He then wrote a lengthy letter to the Queen detailing the foolishness of the French marriage. Characteristically, Elizabeth bristled at his presumption, and Sidney prudently retired from court.

His artistic contacts were more peaceful and more significant for his lasting fame. During his absence from court, he wrote the first draft of The Arcadia and A Defense of Poetry. Somewhat earlier, he had met Edmund Spenser, who dedicated the Shepheardes Calendar to him. Other literary contacts included membership, along with his friends and fellow poets Fulke Greville, Edward Dyer, Edmund Spenser and Gabriel Harvey, of the (possibly fictitious) 'Areopagus', a humanist endeavour to classicize English verse.

Sidney had returned to court by the middle of 1581 and was MP for Kent. That same year Penelope Devereux was married, apparently against her will, to Lord Rich. Sidney was knighted in 1583. An early arrangement to marry Anne Cecil, daughter of Sir William Cecil and eventual wife of de Vere, had fallen through in 1571. In 1583, he married Frances, teenage daughter of Sir Francis Walsingham. The next year, he met Giordano Bruno who subsequently dedicated two books to Sidney.

Both through his family heritage and his personal experience (he was in Walsingham's house in Paris during the St. Bartholomew's Day Massacre), Sidney was a keenly militant Protestant. In the 1570s, he had persuaded John Casimir to consider proposals for a united Protestant effort against the Roman Catholic Church and Spain. In the early 1580s, he argued unsuccessfully for an assault on Spain itself. In 1585, his enthusiasm for the Protestant struggle was given a free rein when he was appointed governor of Flushing in the Netherlands. In the Netherlands, he consistently urged boldness on his superior, his uncle the Earl of Leicester. He conducted a successful raid on Spanish forces near Axel in July, 1586.

Later that year, he joined Sir John Norris in the Battle of Zutphen. During the siege, he was shot in the thigh and died twenty-six days later. According to the story, while lying wounded he gave his water-bottle to another wounded soldier, saying, "Thy necessity is yet greater than mine". This became possibly the most famous story about Sir Phillip, intended to illustrate his noble character.

Sidney's body was returned to London and interred in St. Paul's Cathedral on 16 February 1587. Already during his own lifetime, but even more after his death, he had become for many English people the very epitome of a courtier: learned and politic, but at the same time generous, brave, and impulsive. Never more than a marginal figure in the politics of his time, he was memorialized as the flower of English manhood in Edmund Spenser's Astrophel, one of the greatest English Renaissance elegies.

An early biography of Sidney was written by his friend and schoolfellow, Fulke Greville.

The Rye House conspirator, Algernon Sydney, was Sir Philip's great-nephew.

In Zutphen, the Netherlands, a street has been named after Sir Philip. A statue for him can be found in the park at the Coehoornsingel, where in the harsh winter of 1795 English and Hanoverian soldiers were buried who had died while on retreat for advancing French troops.. A memorial at the location where he was mortally wounded by the Spanish can be found at the entrance of a footpath at the Warnsveldseweg, southeast of the Catholic cemetery.

Books

• Alexander, Gavin. Writing After Sidney: the literary response to Sir Philip Sidney 1586-1640. Oxford: Oxford University Press, 2006.
• Craig, D. H. "A Hybrid Growth: Sidney's Theory of Poetry in An Apology for Poetry." Essential Articles for the Study of Sir Philip Sidney. Ed. Arthur F. Kinney. Hamden: Archon Books, 1986.
• Davies, Norman. A History. London: Pimlico, 1997.
• Duncan-Jones, Katherine. Sir Philip Sidney: Courtier Poet. New Haven and London: Yale University Press, 1991.
• Frye, Northrup. Words With Power: Being a Second Study of the Bible and Literature. Toronto: Penguin Books, 1992.
• Garrett, Martin. Ed. Sidney: the Critical Heritage. London: Routledge, 1996.
• Greville, Fulke.Life of the Renowned Sir Philip Sidney. London, 1652.
• Hale, John. The Civilization of Europe in the Renaissance. New York: Atheeum, 1994.
• Jasinski, James. Sourcebook on Rhetoric: Key Concepts in Contemporary Rhetorical Studies. Thousand Oaks: Sage Publications, 2001.
• Kimbrough, Robert. Sir Philip Sidney. New York: Twayne Publishers, Inc., 1971.
• Leitch, Vincent B., Ed. The Norton Anthology of Theory and Criticism. New York: W. W. Norton & Company, Inc., 2001.
• Lewis, C. S. English Literature in the Sixteenth Century, Excluding Drama. Oxford: Oxford University Press, 1954.
• Robertson, Jean. "Philip Sidney." In The Spenser Encyclopedia. eds. A. C. Hamilton et al. Toronto: University of Toronto Press, 1990.
• Shelley, Percy Bysshe. "A Defence of Poetry." In Shelley’s Poetry and Prose: A Norton Critical Edition. 2nd ed. Eds. Donald H. Reiman and Neil Fraistat. New York: W. W. Norton & Company, 2002.
• Sidney, Philip. A Defence of Poesie and Poems. London: Cassell and Company, 1891.
• The Cambridge History of English and American Literature. Volume 3. Cambridge: Cambridge University Press, 1910.

Articles

• Acheson, Kathy. "' Outrage your face': Anti-Theatricality and Gender in Early Modern Closet Drama by Women." Early Modern Literary Studies 6.3 (January, 2001): 7.1-16. 21 October 2005.
• Bear, R. S. " Defence of Poesie: Introduction. In Renascence Editions. 21 October 2005.
• Griffiths, Matthew. English Court Poets and Petrarchism: Wyatt, Sidney and Spenser. 25 November 2005.
• Harvey, Elizabeth D. Sidney, Sir Philip. In The Johns Hopkins Guide to Literary Theory & Criticism. 25 November 2005.
• Knauss, Daniel, Philip. Love’s Refinement: Metaphysical Expressions of Desire in Philip Sidney and John Donne., Master's Thesis submitted to the Faculty of the North Carolina State University. 25 November 2005.
• Maley, Willy. Cultural Materialism and New Historicism. 8 November 2005
• Mitsi, Efterpi. The "Popular Philosopher": Plato, Poetry, and Food in Tudor Aesthetics. In Early Modern Literary Studies. 9 November 2004.
• Pask, Kevin. "The "mannes state" of Philip Sidney: Pre-scripting the Life of the Poet in England." 25 November 2005.
• Staff. Sir Philip Sidney 1554-1586, Poets' Graves. Accessed 26 May 2008

Other

• Stump, Donald (ed). "Sir Philip Sidney: World Bibliography, Saint Louis University. Accessed 26 May 2008. "This site is the largest collection of bibliographic references on Sidney in existence. It includes all the items originally published in Sir Philip Sidney: An Annotated Bibliography of Texts and Criticism, 1554-1984 (New York: G.K. Hall, Macmillan 1994) as well updates from 1985 to the present."