886 (DCCCLXXXVI) was a common year starting on Saturday of the Julian calendar, the 886th year of the Common Era (CE) and Anno Domini (AD) designations, the 886th year of the 1st millennium, the 86th year of the 9th century, and the 7th year of the 880s decade. As of the start of 886, the Gregorian calendar was 4 days ahead of the Julian calendar, which was the dominant calendar of the time.

• The Glagolitic alphabet, devised by Cyril and Methodius, missionaries from Constantinople, is adopted in the Bulgarian Empire.
• Alfred the Great captures London and renames it Lundenburgh. The boundaries between Wessex and the Danelaw are shifted.
• Alfred the Great builds a small harbour called Queenhythe slightly upstream from London Bridge.
• Alfred the Great mints the first halfpenny. Previous halfpennies had been pennies cut in half.
• Earl Aethelred is given control of London by Alfred the Great. Alfred's sister Ethelfleda marries Aethelred.
• Leo VI succeeds his stepfather Basil I as Byzantine emperor and replaces patriarch Photius with his brother Stephen I.
• Khan Boris I of Bulgaria establishes the Preslav and Ohrid Literary Schools.
• Charles II of France purchases peace with Vikings at Paris.