1550

January–June

• January 6 - Spanish Captain Hernando de Santana founds the city of Valledupar, in modern-day Colombia.
• February 8 - Pope Julius III succeeds Pope Paul III as the 221st pope.
• March 12 - Arauco War: Battle of Penco - Several hundred Spanish and indigenous troops under the command of Pedro de Valdivia defeat an army of 60,000 Mapuche, in modern-day Chile.
• March 24 - "Rough Wooing": England and France sign the Treaty of Boulogne, by which England withdraws from Boulogne in France and returns territorial gains in Scotland.
• March 29 - Sherborne School in England is refounded by King Edward VI.
• April 16 - Valladolid debate on the rights and treatment of indigenous peoples of the Americas by their Spanish conquerors opens at the Colegio de San Gregorio in Valladolid, Castile.
• June 12 - The city of Helsinki, Finland is founded by King Gustav I of Sweden.

  July–December

• July - John Dee finishes his studies at the Old University of Leuven.
• July 7 - Chocolate is introduced to Europe.
• July 21 - The Society of Jesus is approved by Pope Julius III.
• October 2 - Battle of Sauðafell in Iceland: Daði Guðmundsson of Snóksdalur defeats the forces of Catholic Bishop Jón Arason who is captured and executed, resulting in Iceland becoming fully Protestant.

  Date unknown

• Altan Khan crosses the Great Wall of China and besieges Beijing, burning the suburbs.
• The summit level canal between Alster and the Trave in Germany ceases to be navigable.
• The first grammatical description of the French language is published by Louis Maigret.
• The first book in Slovene, Catechismus, written by Protestant reformer Primož Trubar, is printed in Schwäbisch Hall, Holy Roman Empire.
• Nostradamus' first almanac is written.
• Approximate date - The discovery of silver at Zacatecas and Guanajuato in Mexico stimulates silver rushes.

  Births

• January 18 - Tsugaru Tamenobu, Japanese daimyō
• February 1 - John Napier, Scottish mathematician
• February 17 - Philip of Hohenlohe-Neuenstein, Dutch army commander
• February 22 - Charles de Ligne, 2nd Prince of Arenberg
• March 6 - Michelangelo Naccherino, Italian sculptor
• March 8 - William Drury, English politician
• April 5 - Andrés Pacheco, Spanish churchman and theologian
• April 9 - Giulio Pace, Italian philosopher
• April 12 - Edward de Vere, 17th Earl of Oxford, Lord Great Chamberlain of England
• April 16 - Francis Anthony, English apothecary and physician
• April 18 - Alessandro Pieroni, Italian painter
• May 8 - John I, Count Palatine of Zweibrücken
• May 25 - Camillus de Lellis, Italian saint and nurse
• June 16 - Marie Eleonore of Cleves, Duchess consort of Prussia
• June 27 - King Charles IX of France
• June 28 - Johannes van den Driesche, Flemish Protestant clergyman and scholar
• July 3 - Jacobus Gallus, Slovenian composer
• August 6 - Enrico Caetani, Italian Catholic cardinal
• August 8 - Petrus Gudelinus, Belgian jurist
• September 1 - Alonso Pérez de Guzmán, 7th Duke of Medina Sidonia, Spanish admiral
• September 10 - Alonso de Guzmán El Bueno, 7th Duke of Medina Sidonia, commander of the Spanish Armada
• September 17 - Pope Paul V
• September 29 - Joachim Frederick of Brieg, Duke of Wołów
• September 30 - Michael Maestlin, German astronomer and mathematician
• October 1 - Anne of Saint Bartholomew, Spanish Discalced Carmelite nun
• October 4 - King Charles IX of Sweden
• October 8 - Antonio Zapata y Cisneros, Spanish cardinal
• October 25 - Ralph Sherwin, English Roman Catholic priest
• October 28 - Stanislaus Kostka, Polish saint
• November 1 - Henry of Saxe-Lauenburg, Prince-Archbishop of Bremen, Prince-Bishop of Osnabruck and Paderborn
• November 6 - Karin Månsdotter, Swedish queen
• December 2 - Antonio Fernández de Córdoba y Cardona, Spanish diplomat
• December 6 - Orazio Vecchi, Italian composer
• December 21
• * Aegidius Hunnius, German theologian
• * Man Singh I, Mughal noble
• December 22 - Cesare Cremonini, Italian philosopher
• December 28 - Vicente Espinel, Spanish writer
• December 29 - García de Silva Figueroa, Spanish diplomat and traveller
• December 31 - Henry I, Duke of Guise
• date unknown
• * Jacob ben Isaac Ashkenazi, Polish Jewish author
• * Willem Barentsz, Dutch navigator and explorer
• * Anselmus de Boodt, Belgian mineralogist and physician
• * Matthijs Bril, Flemish painter
• * Helena Antonia, Austrian court dwarf
• * Sarsa Dengel, Emperor of Ethiopia
• * Hugh O'Neill, Earl of Tyrone, Irish rebel
• probable
• * Robert Balfour, Scottish philosopher
• * Henry Barrowe, English Puritan and Separatist
• * Emilio de' Cavalieri, Italian composer
• * Cornelis Corneliszoon, Dutch inventor of the sawmill
• * Philip Henslowe, English theatrical entrepreneur
• * Brianda Pereira, Azorean Portuguese heroine

  Deaths

• January 12 - Andrea Alciato, Italian jurist and writer
• January 22 - Jamsheed Quli Qutb Shah, second ruler of Golconda
• January 28 - Magnus III of Mecklenburg-Schwerin, Lutheran administrator of the Prince-Bishopric of Schwerin
• February 22 - Francesco III Gonzaga, Duke of Mantua
• March 7 - William IV, Duke of Bavaria
• March 8 - John of God, Spanish friar and saint
• April 12 - Claude, Duke of Guise, French soldier
• April 13 - Innocenzo Cybo, Italian Catholic cardinal
• April 30 - King Tabinshwehti of Burma
• May 18 - Jean, Cardinal of Lorraine, French churchman
• May 20 - Ashikaga Yoshiharu, Japanese shōgun
• June 13 - Veronica Gambara, Italian poet
• July 19 - Jacopo Bonfadio, Italian historian, executed
• July 22 - Jorge de Lencastre, Duke of Coimbra
• July 30 - Thomas Wriothesley, 1st Earl of Southampton, English politician
• August 18 - Antonio Ferramolino, Italian architect and military engineer
• October 20 - Ferdinand, Duke of Calabria
• October 23 - Tiedemann Giese, Polish Catholic bishop
• October 24 - Louis of Valois, French prince
• October 26 - Samuel Maciejowski, Polish Catholic bishop
• November 6 - Ulrich, Duke of Württemberg
• November 7 - Jón Arason, last Catholic bishop of Iceland
• December 6 - Pieter Coecke van Aelst, Flemish painter
• December 8 - Gian Giorgio Trissino, Italian humanist, poet, dramatist and diplomat
• December 29 - Bhuvanaikabahu VII, King of Kotte
• date unknown - Aq Kubek of Astrakhan, ruler of Astrakhan Khanate