1279 (MCCLXXIX) was a common year starting on Sunday of the Julian calendar, the 1279th year of the Common Era (CE) and Anno Domini (AD) designations, the 279th year of the 2nd millennium, the 79th year of the 13th century, and the 10th and last year of the 1270s decade. As of the start of 1279, the Gregorian calendar was 7 days ahead of the Julian calendar, which was the dominant calendar of the time.

• March 5 – Lithuanian forces led by Traidenis defeat the Teutonic Knights in the Battle of Aizkraukle.
• The first of the Statutes of Mortmain are passed under king Edward I of England, which prevents land from passing into possession of the church.
• The second of two main surveys of the Hundred Rolls, an English census seen as a follow up to the Domesday Book completed in 1086, is begun; it lasts until 1280.
• Al-Razi's important medical writings are translated into Latin by Faraj ben Salim some 350 years after Al-Razi's death.
• The Royal Mint of England moves into the Tower of London.
• Haapsalu town (Estonia) is founded.