100 BC

Year 100 BC was a year of the pre-Julian Roman calendar.

At the time it was known as the Year of the Consulship of Marius and Flaccus (or, less frequently, year 654 Ab urbe condita) and the First Year of Tianhan.[where?]

The denomination 100 BC for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.