|1166 in topic|
|Political entities - State leaders - Religious leaders|
|Birth and death categories|
|Births – Deaths|
|Establishments and disestablishments categories|
|Establishments – Disestablishments|
|Art and literature|
|1166 in poetry|
|Wikimedia Commons has media related to 1166.|
- July – Henry II of England conquers Brittany, granting the territory to his son Geoffrey.
- July 5 – The town of Bad Kleinkirchheim, Austria is first mentioned (in an ecclesiastical document).
- Henry II of England enacts the Assize of Clarendon, reforming English law and defining the legal duties of sheriffs.
- Marko III succeeds Yoannis V as Patriarch of Alexandria.
- Tribhuvanāditya comes to power in the Khmer Empire, following the assassination of Yasovarman II.
- Stefan Nemanja becomes Grand Župan of the Grand Principality of Serbia.
- Henry the Lion has the first bronze statue (a heraldic lion) north of the Alps erected, at Dankwarderode Castle.
- William Marshal, described as "the greatest knight that ever lived," is knighted.
- July 29 – Henry II, Count of Champagne (d. 1197)
- December 24 or 1167 – John, King of England (d. 1216)
- Eudes III, Duke of Burgundy (d. 1218)
- Prithviraj Chauhan of India (d. 1192)
- William de Warenne, 5th Earl of Surrey (d. 1240)
- May 7 – William I of Sicily
- Santa Rosalia, patron saint of Palermo (according to legend; per legend b. 1130)
- Abdul-Qadir Gilani, founder of the Qadiriyyah Sufi Tariqah (b. 1077)