1381 (MCCCLXXXI) was a common year starting on Tuesday of the Julian calendar, the 1381st year of the Common Era (CE) and Anno Domini (AD) designations, the 381st year of the 2nd millennium, the 81st year of the 14th century, and the 2nd year of the 1380s decade. As of the start of 1381, the Gregorian calendar was 8 days ahead of the Julian calendar, which was the dominant calendar of the time.

• June 12– Peasants' Revolt: In England, rebels from Kent and Essex, led by Wat Tyler and Jack Straw, meet at Blackheath. There the rebels are encouraged by a sermon by renegade priest John Ball.
• June 14– Peasants' Revolt: Rebels destroy John of Gaunt's Savoy Palace and storm the Tower of London, killing the Archbishop of Canterbury and the Lord Chancellor. King Richard II of England meets the leaders of the revolt and agrees to reforms such as fair rents and the abolition of serfdom.
• June 15– Peasants' Revolt: During further negotiations, Wat Tyler is murdered by the King's entourage. Noble forces subsequently overpower the rebel army. The rebel leaders are eventually captured and executed and Richard II revokes his concessions.
  • The revolt is discussed in John Gower's Vox Clamantis and Froissart's Chronicles.
• Kęstutis overthrows his nephew, Jogaila, as Grand Duke of Lithuania. Jogaila is allowed to remain as governor of eastern Lithuania.
• Due to Joan I of Naples' support for Antipope Clement VII, Pope Urban VI bestows Naples upon Charles of Durazzo. With the help of the Hungarians, Charles advances on Naples and captures Joan.
• James of Baux, the ruler of Taranto and the Latin Empire, claims the Principality of Achaea after the imprisonment of Joan I of Naples.
• Sonam Drakpa deposes Drakpa Changchub as ruler of Tibet.
• Hajji I succeeds Alah-ad-Din Ali as Mamluk Sultan of Egypt. The Egyptian government continues to be controlled by rebel leader, Berkuk.
• After a naval battle, Venice wins the three-year War of Chioggia against Genoa. The Genoans are permanently weakened by the conflict.
• Timur conquers east Persia, ending the rule of the Sarbadar Dynasty.

• May 9– Johann Schiltberger, German traveller and writer (died 1440)
• October 13 – Thomas FitzAlan, 12th Earl of Arundel, English politician (died 1415)
• John I, Duke of Bourbon (died 1434)
• Saint Rita of Cascia (died 1457)

• March 24– Catherine of Sweden, Swedish saint
• May 15– Eppelein von Gailingen, German robber baron
• June 14– Simon Sudbury, Archbishop of Canterbury
• June 15– John Cavendish, Lord Chief Justice of England
• June 15– Wat Tyler, English rebel
• July 15– John Ball, renegade priest
• December 2– John of Ruysbroeck, Flemish mystic
• December 27– Edmund de Mortimer, 3rd Earl of March, English politician