January 31 – Battle of Gembloux: Spanish forces under Don John of Austria and Alexander Farnese defeat the Dutch. Alexander Farnese begins to recover control of the French-speaking Southern Netherlands.
April 27 – The Duel of the Mignons claims the lives of two favorites of Henry III of France and two favourites of Henry I, Duke of Guise.
May 26 – "The Alteration" in Amsterdam ends Catholic rule and open Catholic worship here.
May 31 – Martin Frobisher sails from Harwich, England to Frobisher Bay, Canada, on his third expedition.
July – Martin Frobisher holds the first celebration of Thanksgiving by Europeans in North America on Newfoundland. He ships ore which proves to be valueless fool's gold which can only be used as road metal in London.
August 4 – Battle of Alcácer Quibir in North Africa: The Moors defeat King Sebastian of Portugal who is killed, leaving his elderly uncle, Cardinal Henry, as his heir, initiating a succession crisis in Portugal.
August 20–September 6 – Francis Drake, during his circumnavigation of the globe, passes through the Strait of Magellan in his ship, the newly renamed Golden Hind.
October 1 – Alessandro Farnese succeeds Don John as Governor of the Spanish Netherlands.
October 21 - Battle of Wenden: The Russians are defeated by the Swedes, who proceed to take Polotsk.
Battle of the Spoiling Dyke at Trumpan in northwest Scotland: the Clan MacLeod are victorious over the MacDonalds of Uist.
The Ottoman Empire conquers Abkhazia.
Sarsa Dengel, Emperor of Ethiopia, kills Bahr negus Yeshaq, finally ending his rebellion.
Sonam Gyrso receives from prince Atlan Khan the title of Talaï, and becomes the third Dalai Lama of Tibet.
Last outbreak of the sweating sickness occurs in England.
January 7 – Agnes of Solms-Laubach, Landgravine of Hesse-Kassel (d. 1602)
January 10 – Christopher Clitherow, Lord Mayor of London and Member of Parliamenter (d. 1641)
January 28 – Cornelius Haga, Dutch diplomat (d. 1654)
March 2 – George Sandys, English traveller (d. 1644)
March 18 – Adam Elsheimer, German artist working in Rome who died at only thirty-two (d. 1610)
April 1 – William Harvey, English physician (d. 1657)
April 14 – King Philip III of Spain (d. 1621)
April 17 – Maximilian van der Sandt, Dutch theologian (d. 1656)
May 11 – Christian Günther I, Count of Schwarzburg-Sondershausen (1601–1642) (d. 1642)
May 16 – Everard Digby, English conspirator (d. 1606)
June 5 – Claude, Duke of Chevreuse, France of Prince (d. 1657)
June 13 – Thomas Finch, 2nd Earl of Winchilsea, Member of Parliament (d. 1639)
July 9 – Ferdinand II, Holy Roman Emperor (d. 1637)
July 21 – Philipp Hainhofer, merchant (d. 1647)
July 27 – Frances Howard, Duchess of Richmond, British duchess (d. 1639)
July 31 – Countess Catharina Belgica of Nassau, regent of Hanau-Münzenberg (d. 1648)
August 5 – Charles d'Albert, duc de Luynes, first duke of Chaulnes (d. 1621)
August 10 – Matteo Rosselli, Italian painter (d. 1650)
Francesco Albani, Italian painter (d. 1660)
Johann, Prince of Hohenzollern-Sigmaringen, first prince of Hohenzollern-Sigmaringen (d. 1638)
August 24 – John Taylor, English poet who dubbed himself "The Water Poet" (d. 1653)
September 11 – Vincenzo Maculani, Catholic cardinal (d. 1667)
September 17 – John Prideaux, Academic administrator and bishop (d. 1650)
October 4 – Giovanni Francesco Guidi di Bagno, Catholic cardinal (d. 1641)
October 12 – Baldassare Aloisi, Italian painter (d. 1638)
October 17 – Dmitry Pozharsky, Russian prince (d. 1642)
October 19 – Christine of Hesse-Kassel, German noblewoman (d. 1658)
November 4 – Wolfgang Wilhelm, Count Palatine of Neuburg, Duke of Jülich and Berg (1614–1635) (d. 1653)
November 6 – Maximilian of Liechtenstein, Austrian nobleman and Imperial General (d. 1645)
December 2 – Agostino Agazzari, Italian composer and music theorist (d. 1640)
December 7 – Okaji no Kata (d. 1642)
December 20 – Henry of Lorraine, Duke of Mayenne, French noble (d. 1621)
December 28 – Henry Bulstrode, English Member of Parliament (d. 1643)
December 30 – Ulrik of Denmark, Danish prince-bishop (d. 1624)
Giambattista Andreini, Italian actor and playwright (d. 1650)
Yamada Arinaga, Japanese retainer of the Shimazu clan (d. 1668)
Benedetto Castelli, Italian scientist (d. 1643)
Thomas Coventry, 1st Baron Coventry, English lawyer (d. 1640)
Iwasa Matabei, Japanese painter (d. 1650)
Samuel Jordan, American colonial legislator (d. 1623)
Grzegorz IV Radziwiłł, Polish magnate (d. 1613)
François Ravaillac, killer of Henry IV of France (d. 1610)
Ambrose Rookwood, English Gunpowder Plot conspirator (d. 1606)
Francis Manners, 6th Earl of Rutland (d. 1632)
Horio Tadauji, Japanese daimyo (d. 1604)
January 5 – Giulio Clovio, Dalmatian painter (b. 1498)
January 25 – Mihrimah Sultan, Sultan Suleiman's daughter (b. 1522)
February 5 – Giovanni Battista Moroni, Italian painter (b. 1510)
Sebastiano Venier, Doge of Venice (b. 1496)
Michael Kantakouzenos Şeytanoğlu, Ottoman Greek magnate
March 7 – Margaret Douglas, Countess of Lennox (b. 1515)
Arthur Champernowne, English admiral (b. 1524)
Louis I, Cardinal of Guise, French cardinal (b. 1527)
April 14 – James Hepburn, 4th Earl of Bothwell, consort of Mary, Queen of Scots (b. 1535)
April 19 – Uesugi Kenshin, Japanese samurai and warlord (b. 1530)
June 20 – Thomas Doughty, English explorer (executed)
July 27 – Jane Lumley, English translator (b. 1537)
King Sebastian of Portugal (b. 1554)
Thomas Stukley, English adventurer (b. 1525)
Abu Marwan Abd al-Malik I Saadi, King of Morocco
Abu Abdallah Mohammed II Saadi, King of Morocco
August 8 – Amago Katsuhisa, Japanese nobleman (b. 1553)
August 11 – Pedro Nunes, Portuguese mathematician (b. 1502)
September – Pierre Lescot, French architect (b. 1510)
October 1 – Don John of Austria, military leader (b. 1547)
December – Nicholas Heath, Archbishop of York and Lord Chancellor of England (b. 1501)
Ikeda Katsumasa, Japanese military commander (b. 1539)
Sabina, Duchess of Bavaria (b. 1528)
Year 1578 (MDLXXVIII) was a common year starting on Wednesday (link will display the full calendar) of the Julian calendar.