|Millennium:||1st millennium BC|
|73 BC by topic|
|Gregorian calendar||73 BC|
|Ab urbe condita||681|
|Ancient Egypt era||XXXIII dynasty, 251|
|- Pharaoh||Ptolemy XII Auletes, 8|
|Ancient Greek era||176th Olympiad, year 4|
|Balinese saka calendar||N/A|
|Chinese calendar||丁未年 (Fire Goat)|
2624 or 2564
— to —
戊申年 (Earth Monkey)
2625 or 2565
|Coptic calendar||−356 – −355|
|Ethiopian calendar||−80 – −79|
|- Vikram Samvat||−16 – −15|
|- Shaka Samvat||N/A|
|- Kali Yuga||3028–3029|
|Iranian calendar||694 BP – 693 BP|
|Islamic calendar||715 BH – 714 BH|
|Minguo calendar||1984 before ROC|
|Seleucid era||239/240 AG|
|Thai solar calendar||470–471|
54 or −327 or −1099
— to —
55 or −326 or −1098
Year 73 BC was a year of the pre-Julian Roman calendar. At the time it was known as the Year of the Consulship of Lucullus and Longinus (or, less frequently, year 681 Ab urbe condita). The denomination 73 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.
- Third Servile War: Spartacus, a Thracian gladiator, escapes with around 70 slave-gladiators from a gladiator school at Capua. They defeat a small Roman force and equip themselves with captured military equipment as well with gladiatorial weapons. Spartacus and his band of gladiators plunder the region surrounding Capua and retire to a defensible position on Mount Vesuvius.
- Battle of Mount Vesuvius: Spartacus defeats a Roman militia force (3,000 men) under Gaius Claudius Glaber. The rebel slaves spend the winter of 73–72 BC training, arming and equipping their new recruits, as well as expanding their raiding territory, which includes the towns of Nola, Nuceria, Thurii and Metapontum.
- Herod the Great, client king of Judea (d. 4 BC)
- Marcus Porcius Cato, assassin of Julius Caesar (d. 42 BC)
- Devabhuti, king of the Shunga Empire
- Gaius Aurelius Cotta, Roman statesman and orator
- Heli, king of Britain (approximate date)
- ^ Appian, Civil Wars, 1:116; Florus, Epitome, 2.8; - Florus and Appian make the claim that the slaves withdrew to Mount Vesuvius, while Plutarch only mentions "a hill" in the account of Glaber's siege of the slave's encampment.
- ^ "Herod | Biography & Facts". Encyclopedia Britannica. Retrieved April 7, 2019.