Year 1376 (MCCCLXXVI) was a leap year starting on Tuesday of the Julian calendar.

• March – The peace treaty between England and France is extended until April, 1377.
• March 31 – Pope Gregory XI excommunicates all members of the government of Florence, and places the city under an interdict.
• April 28 – The Good Parliament begins in England (so called because its members attempted to reform the corrupt Royal Council on that date).
• May 3 – Olav IV Haakonsson is elected King Oluf II of Denmark, following the death of his grandfather, Valdemar IV, in 1375.
• June – Catherine of Siena visits Pope Gregory XI in Avignon, to attempt to persuade him to make peace with Florence, and move the Papacy back to Rome.
• June 7 – The dying Prince Edward summons his father, Edward III, and brother, John of Gaunt, and makes them swear to uphold the claim to the throne of his son Richard; Edward is the first "English" Prince of Wales not to become King of England.
• July 10 – The Good Parliament is dissolved (at that time, it was the longest Parliament to have sat in England).
• August 12 – With the help of the Genoese, Byzantine co-emperor Andronicus IV Palaeologus invades Constantinople and dethrones his father, John V Palaeologus, as co-emperor. John V Palaeologus is taken prisoner.
• September – John of Gaunt summons religious reformer John Wyclif to appear before the Royal Council.
• November 20 – Richard of Bordeaux, son of the Black Prince, is created Prince of Wales in succession to his father.
• December 25 – John of Gaunt presents his nephew, Richard of Bordeaux, to the feudatories of the realm and swears to uphold Richard's right to succeed Edward III.

• Acamapichtli becomes the first tlatoani of Tenochtitlan.

• November 9 – Edmund Mortimer, English nobleman and rebel (d. c. 1409)
• date unknown
  • Gihwa, scholar in Korean Buddhism (d. 1433)
  • Sofia of Bavaria, queen consort of Bohemia (d. 1425)
  • Yusuf III, Sultan of Granada (d. 1417)

• January 24 – Richard FitzAlan, 10th Earl of Arundel, English military leader
• April 6 – Przecław of Pogorzela, Cardinal and Bishop of Wrocław (b. 1310)
• May 30 – Joan of Ponthieu, Dame of Epernon, French countess regent
• June 8 – Edward, the Black Prince, son of King Edward III of England (b. 1330)^[1]
• July 22 – Simon Langham, Archbishop of Canterbury (b. 1310)
• September 30 – Adelaide of Vianden, German countess^[2][3]