Year 1531 (MDXXXI) was a common year starting on Sunday (link will display the full calendar) of the Julian calendar.
January 26 – Lisbon, Portugal is hit by an earthquake in which thousands die.
February 27 – Lutheran princes in the Holy Roman Empire form an alliance known as the Schmalkaldic League.
February or March – Battle of Antukyah: Ahmad ibn Ibrahim al-Ghazi of the Adal Sultanate defeats the Ethiopian army.
April – Battle of Puná: Francisco Pizarro defeats the island's native inhabitants.
April 16 – The city of Puebla, Mexico, is founded.
May – The third Dalecarlian rebellion in Sweden appears to be over when the king accepts an offer made by the rebels, but violence flares up again the following year.
June 24 – The city of San Juan del Río, Mexico, is founded.
July 25 – The city of Santiago de Querétaro, Mexico is founded.
August 26 – Comet Halley achieves its perihelion.
September 22 – Battle of Obertyn: The Moldavians are defeated by Polish forces under Jan Tarnowski, allowing the Poles to recapture Pokucie.
October 11 – Battle of Kappel: The forces of Zürich are defeated by the Catholic cantons. Huldrych Zwingli, the Swiss religious reformer, is killed.
October 28 – Battle of Amba Sel: Imam Ahmad ibn Ibrahim al-Ghazi again defeats the army of Lebna Dengel, Emperor of Ethiopia. The southern part of Ethiopia thus falls under Imam Ahmad's control.
December 12 – Mary, mother of Jesus, in the guise of Our Lady of Guadalupe, appears imprinted on the tilmàtli of Juan Diego Cuauhtlatoatzin, an Aztec convert to Catholicism, in Tepeyacac near Mexico City.
Andrea Alciato publishes the first part of his Emblemata.
Conquistador Francisco de Montejo claims Chichen Itza as capital of Spanish-ruled Yucatán.
The University of Sarajevo is founded by Gazi Husrev-beg.
Kõpu Lighthouse is completed.
An enormous drought in Henan province, China, coupled with a gigantic swarm of locusts in the summer, forces many in destitute agricultural communities to turn to cannibalism instead of dying by starvation.
Charles V, Holy Roman Emperor abolishes the worst abuses of the encomienda system by pressure of Bartolomé de las Casas.
Witch-hunt in the town of Schiltach, Germany.
January 1? – John Popham, Lord Chief Justice of England (d. 1607)
January 26 – Jens Bille, son of Claus Bille and Lisbeth Ulfstand (d. 1575)
April 6 – Wolfgang, Duke of Brunswick-Grubenhagen (d. 1595)
May 15 – Maria of Austria, Duchess of Jülich-Cleves-Berg, daughter of Emperor Ferdinand I (d. 1581)
May 20 – Thado Minsaw of Ava, Viceroy of Ava (d. 1584)
June 1 – János Zsámboky, Hungarian scholar (d. 1584)
July 17 – Antoine de Créqui Canaples, Roman Catholic cardinal (d. 1574)
July 22 – Leonhard Thurneysser, scholar and quack at the court of John George, Elector of Brandenburg (d. 1595)
September 2 – Francesco Cattani da Diacceto, Bishop of Fiesole (d. 1595)
September 4 – Hans Fugger, German businessman (d. 1598)
September 14 – Philipp Apian, German mathematician and medic (d. 1589)
Late September – Henry Stanley, 4th Earl of Derby, English noble and diplomat (died 1594)
October 7 – Scipione Ammirato, Italian historian (d. 1601)
October 12 – Jacques de Savoie, 2nd Duc de Nemours (d. 1585)
October 25 – Matthew Wesenbeck, Belgian jurist (d. 1586)
October 27 – Herbert Duifhuis, Dutch minister (d. 1581)
November 14 – Richard Topcliffe, English torturer (died 1604)
November 16 – Anna d'Este, Duchess consort of Nemours (d. 1607)
November 18 – Roberto di Ridolfi, Italian conspirator against Elizabeth I of England (died 1612)
November 29 – Johannes Letzner, German Protestant priest and historian (d. 1613)
December – Hendrick van Brederode, Dutch noble (died 1568)
December 6 – Vespasiano I Gonzaga, Italian noble and diplomat (d. 1591)
December 9 – Şehzade Cihangir, Ottoman prince (d. 1553)
December 10 – Henry IX, Count of Waldeck (d. 1577)
date unknown
Akiyama Nobutomo, Japanese nobleman (died 1575)
António, Prior of Crato, claimant to the throne of Portugal (died 1595)
January 21 – Andrea del Sarto, Italian painter (born 1487)
February 16 – Johannes Stöffler, German mathematician (born 1452)
March 6 – Pedrarias Dávila, Spanish colonial administrator (born c. 1440)
May 19 – Jan Łaski, Polish statesman and diplomat (born 1456)
July 7 – Tilman Riemenschneider, German sculptor (born 1460)
July 17 – Hosokawa Takakuni, Japanese military commander (born 1484)
July 23 – Louis de Brézé, seigneur d'Anet, Marshal of Normandy and husband of Diane de Poitiers
October 11 – Huldrych Zwingli, Swiss reformer (in battle) (born 1484)
September 22 – Louise of Savoy, French regent (born 1476)
November 24 – Johannes Oecolampadius, German religious reformer (born 1482)
date unknown
María Pacheco, Spanish heroine and defender of Toledo (born 1496)
Vallabha Acharya, founder of the Hindu Vallabha sect (born 1479)
Gerónimo de Aguilar, Franciscan friar who participated in the Spanish conquest of Mexico (b. 1489)
probable – Fernan Perez de Oliva, Spanish man of letters (born 1492)
1531 Wikipedia (Text) CC BY-SA