Year 1076 (MLXXVI) was a leap year starting on Friday of the Julian calendar.

• January 24 – Synod of Worms: Emperor Henry IV, Holy Roman Emperor, holds a synod in Worms (modern Germany). The assembly declares Pope Gregory VII deposed, and the bishops abandon their allegiance to him.
• February 22 – Gregory VII pronounces a sentence of excommunication against Henry IV at Rome. He is excluded from the Catholic Church, and all the bishops named by Henry are excommunicated.
• Summer – Dirk V, count of Holland, re-conquers West Frisia (modern Netherlands) from the Archdiocese of Utrecht. He besieges Bishop Conrad at the castle of IJsselmonde, taking him prisoner.
• October 8 – Demetrius Zvonimir is crowned as king of Croatia in Solin (near Split), in the Basilica of Saint Peter and Moses (known later as the Hollow Church) by a representative of Gregory VII.
• December 13 – Norman conquest of southern Italy: Italo-Norman forces under Robert Guiscard de Hauteville and Richard I of Capua, conquer the fortress city of Salerno after a short siege.
• December 26 – Bolesław II the Bold (or "the Generous") is crowned as King of Poland by Archbishop Bogumił in Gniezno Cathedral. Bolesław supports Gregory VII in his conflict against Henry IV.

• May 31 – Waltheof, Earl of Northumbria, a participant in the Revolt of the Earls against King William the Conqueror, is beheaded near Winchester.
• November 1 – A frost begins that lasts until April 1077.^[1]
• Approximate date – The Trial of Penenden Heath is held, with an important ruling regarding land rights subsequent to the Norman Conquest.

• Approximate date – Koumbi Saleh, an important mercantile and political center of the Ghana Empire (modern Mauritania), is besieged by the Almoravids.

• Vikramaditya VI deposes his older brother Someshvara II to become king of the Western Chalukya Empire (modern India).

• Anselm of Aosta, an Italian Benedictine abbot, completes his Monologion at the request of his fellow monks.

• Demetrius Zvonimir donates the Benedictine monastery of St. Gregory in Vrana to Gregory VII.

• June 1 – Mstislav I "the Great"), Grand Prince of Kyiv (d. 1132)
• Fujiwara no Sadazane, Japanese calligrapher (d. 1120)
• Urban (or Gwrgan), bishop of Llandaff (d. 1134)
• Approximate date
  • Abu Bakr ibn al-Arabi, Moorish scholar and judge (d. 1148)
  • Hualani, Hawaiian queen and regent

• February 26 or 27 – Godfrey the Hunchback, duke of Lower Lorraine
• March 18 – Ermengarde of Anjou, duchess of Burgundy
• March 21 – Robert I ("the Old"), duke of Burgundy (b. 1011)
• April 18 – Beatrice of Bar, French duchess and regent
• April 28 – Sweyn II Estridsson, king of Denmark
• May 8 – Nasr ibn Mahmud, Mirdasid emir of Aleppo
• May 26 – Ramon Berenguer I, count of Barcelona (b. 1023)
• May 31 – Waltheof, earl of Northumbria (executed)
• June 4 – Sancho IV, king of Pamplona (or Navarre)
• July 15 – Arnost (or Arnošt), bishop of Rochester
• Ramihrdus of Cambrai, French heretic priest and martyr (or 1077)
• William Busac, French nobleman (jure uxoris) (b. 1020)