90 BC

Millennium:	1st millennium BC
Centuries:	2nd century BC – 1st century BC – 1st century
Decades:	120s BC 110s BC 100s BC – 90s BC – 80s BC 70s BC 60s BC
Years:	93 BC 92 BC 91 BC – 90 BC – 89 BC 88 BC 87 BC

90 BC by topic
Politics
State leaders – Sovereign states
Birth and death categories
Births – Deaths
Establishments and disestablishments categories
Establishments – Disestablishments

**90 BC in other calendars**
Gregorian calendar	90 BC
Ab urbe condita	664
Armenian calendar	N/A
Bahá'í calendar	-1933 – -1932
Bengali calendar	-682
Berber calendar	861
Buddhist calendar	455
Burmese calendar	-727
Byzantine calendar	5419 – 5420
Chinese calendar	[[Sexagenary cycle\|]]年 (2547/2607) — to — [[Sexagenary cycle\|]]年 (2548/2608)
Coptic calendar	-373 – -372
Ethiopian calendar	-97 – -96
Hebrew calendar	3671 – 3672
Hindu calendars
- Bikram Samwat	-33 – -32
- Shaka Samvat	N/A
- Kali Yuga	3012 – 3013
Holocene calendar	9911
Iranian calendar	711 BP – 710 BP
Islamic calendar	733 BH – 732 BH
Japanese calendar
Korean calendar	2244
Thai solar calendar	454

Year 90 BC was a year of the pre-Julian calendar.

Events

Consuls: Lucius Julius Caesar and Publius Rutilius Lupus.
Social War continues: Pompeius Strabo and Gaius Marius distinguish themselves.
The Etruscans are granted Roman citizenship.
Corfinium in south-central Italy is the center of a rebellion against Rome.
The Lex Iulia grants citizenship to all Italians who did not oppose Rome during the Social War.
Cicero starts to serve in the Roman army.

Nicomedes IV of Bithynia is defeated in battle by a coalition of Nicomedes' brother Socrates, and Mithridates VI of Pontus. Nicomedes flees to Rome.