86 BC is the first century BC (Before Christ). BC is a designation used to label or number years in the Julian and Gregorian calendars that precede the year 1 AD (Anno Domini which is Latin for "in the year of the Lord").
The centuries in relation to 86 BC are as follows:
- 7th century BC
- 6th century BC
- 5th century BC
- 4th century BC
- 3rd century BC
- 2nd century BC
- 1st century BC (86 BC)