|Millennium:||1st millennium BC|
|63 BC by topic|
|Gregorian calendar||63 BC|
|Ab urbe condita||691|
|Ancient Egypt era||XXXIII dynasty, 261|
|- Pharaoh||Ptolemy XII Auletes, 18|
|Ancient Greek era||179th Olympiad, year 2|
|Balinese saka calendar||N/A|
|Chinese calendar||丁巳年 (Fire Snake)|
2634 or 2574
— to —
戊午年 (Earth Horse)
2635 or 2575
|Coptic calendar||−346 – −345|
|Ethiopian calendar||−70 – −69|
|- Vikram Samvat||−6 – −5|
|- Shaka Samvat||N/A|
|- Kali Yuga||3038–3039|
|Iranian calendar||684 BP – 683 BP|
|Islamic calendar||705 BH – 704 BH|
|Minguo calendar||1974 before ROC|
|Seleucid era||249/250 AG|
|Thai solar calendar||480–481|
64 or −317 or −1089
— to —
65 or −316 or −1088
Year 63 BC was a year of the pre-Julian Roman calendar. At the time it was known as the Year of the Consulship of Cicero and Hybrida (or, less frequently, year 691 Ab urbe condita). The denomination 63 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.
- Lucullus holds a triumph, then retires from war and politics to live a life of refined luxury.
- Establishment of the Decapolis and Year 1 of the Pompeian era.
- Pompey conquers the people of Phonecia, Coele-Syria, and Judea for the Roman Republic.
- Roman annexation of Judea as a client kingdom. King Judah Aristobulus II removed from power, while his brother John Hyrcanus II is reappointed king (ethnarch) under Roman suzerainty and high priest, until 40 BC.
- Massacre of over 12,000 Jews on the Temple Mount in Jerusalem by Roman troops, in support of John Hyrcanus II against Aristobulus II.
- Julius Caesar is elected Pontifex Maximus and praetor for 62 BC.
- Marcus Tullius Cicero is senior consul. He is the first novus homo (new man) to be elected to the consulship in 31 years.
- Cato the Younger is elected tribune of the people for 62 BC, taking office in early December 63 BC.
- Second Catilinarian Conspiracy against the Roman Republic is foiled by Cicero.
- September 23 – Gaius Octavius Thurinus (Augustus), first Roman Emperor (d. AD 14)
- Strabo, Greek historian, geographer and philosopher (d. c. AD 24)
- Didymus Chalcenterus, Greek scholar and grammarian (approximate date) (d. c. AD 10)
- Marcus Vipsanius Agrippa, Roman statesman and general (d. 12 BC)
- Those involved in the organisation of the Catilinarian conspiracy in Rome, including Publius Cornelius Lentulus Sura
- Mithridates VI, King of Pontus (b. 135 BC)
- Quintus Caecilius Metellus Pius, pontifex maximus and general (b. c. 130 BC or 127 BC)