In the year 1580...
- When King Henry of Portugal dies without an heir, Spanish forces under the Duque de Alba conquer the country for King Philip II of Spain, who has a claim to the throne as the son of Isabella of Portugal who was daughter of King Manuel I. Portugal would remain part of Spain until 1640.
- English born Jesuits Robert Persons and Edmund Campion embark on a secret mission to win converts to Roman Catholicism in England, initiating a nationwide manhunt that will end the following year with Campion's capture and execution and Person's escape to the continent.
- A seventh War of Religion briefly erupts in France, as Henry of Navarre spars for power with Catherine de Medici.
- Francis Drake returns to Plymouth after four years at sea as the first Englishman to circumnavigate the Earth, bearing an enormous treasure captured from Spanish ships. Queen Elizabeth I is so pleased with Drake that she personally knights him on the deck of his ship, the Golden Hind.
- Spanish conquistador Juan de Garay refounds Buenos Aires, which had been abandoned since 1541.
- Michel de Montaigne publishes the first two volumes of his Essays.
- English author John Lyly publishes Euphues and His England, the second part of his novel of manners Euphes.
- Polish poet Jan Kochanowski publishes Laments, a collection of elegies on the death of his daughter.
- The Book of Concord, a collection of the authoritative confessions of faith of the Lutheran Church, is published to mark the 50th anniversary of the Augsburg Confession.
- French potter and writer Bernard Palissy publishes his Discours admirables - diverse writings on religion, chemistry, philosophy, and natural history.
- In response to the attacks made by Stephen Gosson in The School of Abuse (1579), Sir Philip Sidney publishes Apologie for Poetrie and Defense of Poesie and Thomas Lodge publishes Honest Excuses.
- John Stow publishes his history Chronicles of England, better known as Annales of England from its title in the edition of 1592.
These people were born in 1580:
- Protestant general in the Thirty Years War Peter Ernst von Mansfeld.
- Gabriel Bethlen, future prince of Transylvania.
- Wampanoag chief Massasoit, who would befriend the Pilgrims in 1621 (approximate).
- English colonist to Virginia John Smith, who would allegedly be saved from death by Pocahontas.
- Dutch colonial administrator Peter Minuit, who in 1626, as director-general of New Netherland colony, would purchase Manhattan from Native Americans for trinkets worth about $400 modern dollars.
- George Calvert, First Baron Baltimore, founder of Maryland.
- French priest and future saint Vincent de Paul (approximate).
- Scottish general Alexander Leslie, First earl of Leven.
- Dutch painter Frans Hals (approximate).
- Portuguese poet Francisco Rodrigues Lobo.
- Spanish writer Francisco de Quevedo y Villegas.
- Italian sculptor Fancesco Mochi.
- English playwright Thomas Middleton.
- English playwright John Webster.
- Dutch classical scholar Daniel Heinsius.
- English diplomat John Digby, First Earl of Bristol.
These people died in 1580:
1579 | 1581