Year 1015 (MXV) was a common year starting on Saturday of the Julian calendar.

• October – Influential Japanese statesman Fujiwara no Michinaga is appointed to be Associate Regent.
• November – The newly constructed Japanese imperial residence burns down.
• Peacocks arrive from the Chinese Song Empire to Fujiwara's mansion in Japan.

• July 15 – Vladimir the Great dies at Berestove after a 35-year reign. He is succeeded by his son Sviatopolk I as Grand Prince of Kiev.
• Summer – King Cnut the Great of Denmark launches an invasion of Mercia and Northumbria in England.^[1]
• Emperor Henry II launches a German expedition against Duke Bolesław I the Brave. He invades Poland, but is stopped by Bolesław's forces at Krosno, on the Oder River.
• Earl Eric Haakonsson outlaws berserkers in Norway.
• Olaf Haraldsson declares himself King of Norway.

• Andrew I ("the Catholic"), king of Hungary (d. 1060)
• Altmann, bishop of Passau (approximate date)
• Ermesinda of Bigorre, queen of Aragon (d. 1049)
• Eustace II, count of Boulogne (approximate date)
• Ferdinand I, king of León and Castile (d. 1065)
• Frozza Orseolo, margravine of Austria (d. 1071)
• Harald Hardrada, king of Norway (d. 1066)
• Herman IV, duke of Swabia (approximate date)
• John Komnenos, Byzantine aristocrat (d. 1067)
• Michael V Kalaphates, Byzantine emperor (d. 1042)
• Otto II, margrave of Montferrat (approximate date)
• Robert Guiscard, Norman nobleman (d. 1085)
• Roger de Beaumont, Norman nobleman (d. 1094)

• February 5 – Adelaide, German abbess and saint
• February 13 – Gilbert of Meaux, French bishop
• July 15 – Vladimir the Great, Grand Prince of Kiev
• September 1 – Gero II, margrave of the Saxon Ostmark
• September 12 – Lambert I, count of Louvain (b. 950)
• December 14 – Arduin of Ivrea, king of Italy (b. 955)
• December 20 – Eido I, bishop of Meissen (b. 955)
• date unknown
  • Æthelmær the Stout, English ealdorman
  • Al-Sharif al-Radi, Persian Shi'ite scholar (b. 970)
  • Gavril Radomir, emperor (tsar) of Bulgaria
  • Geoffrey (or Godfrey), count of Eu (b. 962)
  • Herbert III, count of Vermandois (b. 953)
  • Hugh III, count of Maine (approximate date)
  • Ibn Furak, Muslim imam and theologian (b. 941)
  • Irene of Larissa, empress (tsarina) of Bulgaria
  • Liu Zong, Chinese official of the Song Dynasty
  • Masawaih al-Mardini, Syrian physician and writer
  • Morcar (or Morkere), English minister (thegn)
  • Owain ap Dyfnwal, king of Strathclyde (Scotland)
  • Rodulf of Ivry, Norman nobleman (approximate date)
  • Sigeferth (or Sigefrith), English chief minister
  • Vikramaditya V, Indian ruler of the Chalukya Empire