|Covid-19|April – The House of Balsic's rule of Montenegro comes to an end with the death of Balša III.
August 4 – Hussite Wars – Battle of Tachov: The Hussites decisively beat the crusader armies, ending the Fourth Anti-Hussite Crusade.
August 17 – The first band of Gypsies visits Paris, according to an account of the citizen of Paris.
Lincoln College, a constituent college of the University of Oxford, is founded.
Bhaktapur Royal Palace in Nepal is built by King Yaksa Malla.
Gabriel V is elected Patriarch of the Coptic Church for the second time.
Minrekyansa becomes King of Ava (ancient Burma).
The Conflict of Druimnacour occurs in Sutherland, Scotland.
The first witch hunts begin, in Switzerland.
Celestine Order established in France.
The Celebration of Sant Jordi (Saint George) begins in Catalonia (he will later become its patron saint).
Bremen is expelled from the Hanseatic League.
Diogo de Silves, Portuguese navigator, discovers seven islands of the Azores archipelago.
The Battle of the Echinades, between a Byzantine fleet and the fleet of Carlo I Tocco.
February 27 – Ruprecht, Archbishop of Cologne (d. 1480)
May 8 – John Tiptoft, 1st Earl of Worcester, Lord High Treasurer (d. 1470)
May 29 – Françoise d'Amboise, Member of the French nobility, co-founder of the first monastery of the Carmelites in France (d. 1485)
June 22 – Lucrezia Tornabuoni, Wife of Piero di Cosimo de' Medici (d. 1482)
September 9 – Thomas de Ros, 9th Baron de Ros, English politician (d. 1464)
October 26 – Archduke Sigismund of Austria (d. 1496)
November 24 – John Stafford, 1st Earl of Wiltshire (d. 1473)
November 29 – Zhengtong Emperor of China (d. 1464)
November 30 – Casimir IV Jagiellon, King of Poland (d. 1492)
date unknown – Shen Zhou, Chinese painter (d. 1509)
April 17 – John IV, Duke of Brabant (b. 1403)
May 7 – Thomas la Warr, 5th Baron De La Warr, English churchman
Chimalpopoca, Aztec ruler of Tenochtitlán (b. 1397)
Qu You, Chinese novelist (b. 1341)
Jehuda Cresques, Catalan cartographer (b. 1350)
Gentile da Fabriano, Italian painter
Year 1427 (MCDXXVII) was a common year starting on Wednesday (link will display the full calendar) of the Julian calendar.