1075 (MLXXV) was a common year starting on Thursday (link will display the full calendar) of the Julian calendar.
|Centuries:||10th century – 11th century – 12th century|
|Decades:||1040s 1050s 1060s – 1070s – 1080s 1090s 1100s|
|Years:||1072 1073 1074 – 1075 – 1076 1077 1078|
- February – Pope Gregory VII holds a council that publishes a decree against lay investiture.
- April – Pope Gregory VII publishes the Dictatus Papae (Sayings of the Pope, aka the Dictates of Hildebrand), in which he asserts papal authority over earthly as well as spiritual rulers.
- Revolt of the Earls: Three earls rebel against William I of England (William the Conqueror), in the last serious act of resistance to the Norman Conquest.
- First Battle of Langensalza: Henry IV, Holy Roman Emperor defeats the Saxon nobles and subjugates Saxony.
- The Liao Dynasty version of the Buddhist Tripitaka is completed (approximate date).
- Anund Gårdske is removed as king of Svealand and king Håkan the Red of Gothenland makes himself king of all Sweden.
- The Seljuk Turks take Jerusalem from the Fatimids.
- Lý dynasty forces under Lý Thường Kiệt defend Vietnam against invasion by Song Dynasty China.
- The Song Dynasty Chinese polymath scientist and statesman Shen Kuo solves a border dispute with the Liao Dynasty by finding old diplomatic records; he argues Emperor Daozong of Liao's bluffs point for point during a meeting at Mt. Yongan (near modern Pingquan in Hebei), and reestablishes the Song's borders.
- June 9 – Lothair II, Holy Roman Emperor (d. 1137)
- Saint Magnus Erlendsson (d. 1116 or 1117)
- Adelaide del Vasto (d. 1118)
- Orderic Vitalis, monk and historian (approximate date)
- June 10 – Ernest of Austria (b. 1027)
- August 2 – Patriarch John VIII of Constantinople
- December 4 – Anno II, archbishop of Cologne
- December 19 – Edith of Wessex, queen of Edward the Confessor of England
- John Xiphilinus, Byzantine historian
- Bleddyn ap Cynfyn, King of Gwynedd
- Peter Krešimir IV, King of Croatia