|Millennium:||1st millennium BC|
|Centuries:||3rd century BC – 2nd century BC – 1st century BC|
|Decades:||130s BC 120s BC 110s BC – 100s BC – 90s BC 80s BC 70s BC|
|Years:||111 BC 110 BC 109 BC – 108 BC – 107 BC 106 BC 105 BC|
|108 BC by topic|
|Gregorian calendar||108 BC|
|Ab urbe condita||646|
|Bahá'í calendar||−1951 – −1950|
|English Regnal year||N/A|
|Chinese calendar||壬申年 (Water Monkey)
2589 or 2529
— to —
癸酉年 (Water Rooster)
2590 or 2530
|Coptic calendar||−391 – −390|
|Ethiopian calendar||−115 – −114|
|- Vikram Samvat||−51 – −50|
|- Shaka Samvat||N/A|
|- Kali Yuga||2994–2995|
|Igbo calendar||−1107 – −1106|
|Iranian calendar||729 BP – 728 BP|
|Islamic calendar||751 BH – 750 BH|
|Minguo calendar||2019 before ROC
|Thai solar calendar||436|
|Wikimedia Commons has media related to 108 BC.|
Year 108 BC was a year of the pre-Julian Roman calendar. At the time it was known as the Year of the Consulship of Galba and Hortensius/Scaurus (or, less frequently, year 646 Ab urbe condita). The denomination 108 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.
- Roman forces under Quintus Caecilius Metellus Numidicus defeat the forces of Jugurtha of Numidia at the Battle of the Muthul, with Gaius Marius as a subordinate.
- The Korean kingdom of Wiman Joseon falls, and Chinese Emperor Wu of Han establishes the Lelang Commandery in northern Korea.
- December – The Han Dynasty Chinese under commander Zhao Ponu are victorious in the Battle of Loulan in the Tarim Basin, resulting in the submission of Dayuan and the Wusun in Central Asia.