|Millennium:||1st millennium BC|
|88 BC by topic|
|Gregorian calendar||88 BC|
|Ab urbe condita||666|
|Ancient Egypt era||XXXIII dynasty, 236|
|- Pharaoh||Ptolemy IX Lathyros, 1|
|Ancient Greek era||173rd Olympiad (victor)¹|
|Balinese saka calendar||N/A|
|Chinese calendar||壬辰年 (Water Dragon)|
2609 or 2549
— to —
癸巳年 (Water Snake)
2610 or 2550
|Coptic calendar||−371 – −370|
|Ethiopian calendar||−95 – −94|
|- Vikram Samvat||−31 – −30|
|- Shaka Samvat||N/A|
|- Kali Yuga||3013–3014|
|Iranian calendar||709 BP – 708 BP|
|Islamic calendar||731 BH – 730 BH|
|Minguo calendar||1999 before ROC|
|Seleucid era||224/225 AG|
|Thai solar calendar||455–456|
39 or −342 or −1114
— to —
40 or −341 or −1113
Year 88 BC was a year of the pre-Julian Roman calendar. At the time it was known as the Year of the Consulship of Sulla and Rufus (or, less frequently, year 666 Ab urbe condita). The denomination 88 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.
- The Social War ends with the defeat of the Italian allies by the Romans. Lucius Cornelius Sulla, age 50, becomes the first Roman commander to march on Rome with his army and to capture the city by force. This extraordinary act is prompted by his desire to maintain his consular command for the First Mithridatic War in Asia Minor.
- The First Roman Civil War starts with a democratic uprising led by Gaius Marius, but the democrats under the tribune P. Sulpicius Rufus are crushed by the conservatives under Sulla. Marius flees to Africa.
- First Civil War in Rome, between Marius and Sulla. Some Italian cities are destroyed: for instance, Forlì, rebuilt by the praetor Livius Clodius afterwards.
- The Dardani, Scordisci, and the Maedi attack the Roman province of Macedonia.
- May – King Mithridates VI of Pontus invades Greece. Defeating the Roman forces four times in succession, he conquers Bithynia, Phrygia, Mysia, Lycia, Pamphylia, Ionia and Cappadocia. The Roman province of Asia is dismantled. On the king's orders, the local authorities in every city of the province round up and put to death all resident Italians – men, women and children – in a single day (App.Mith.§§85–91). Plutarch (Sulla 24.4) says that 150,000 are killed, other sources calculate a figure of 80,000 people.
- Demetrius III Eucaerus, king of the Seleucid Empire
- Gnaeus Domitius Ahenobarbus, Roman consul
- Lady Gouyi, mother of Zhao of Han (b. 113)
- Li Guangli, Chinese general (Han Dynasty)
- Manius Aquillius, Roman consul and general
- Ptolemy X Alexander I, king (pharaoh) of Egypt
- Publius Sulpicius Rufus, Roman statesman
- Quintus Mucius Scaevola Augur, Roman consul
- Quintus Poppaedius Silo, Italian tribe leader