|Millennium:||1st millennium BC|
|Centuries:||6th century BC – 5th century BC – 4th century BC|
|Decades:||460s BC 450s BC 440s BC – 430s BC – 420s BC 410s BC 400s BC|
|Years:||433 BC 432 BC 431 BC – 430 BC – 429 BC 428 BC 427 BC|
|430 BC by topic|
|Gregorian calendar||430 BC|
|Ab urbe condita||324|
|Ancient Egypt era||XXVII dynasty, 96|
|- Pharaoh||Artaxerxes I of Persia, 36|
|Ancient Greek era||87th Olympiad, year 3|
|Chinese calendar||庚戌年 (Metal Dog)
2267 or 2207
— to —
辛亥年 (Metal Pig)
2268 or 2208
|Coptic calendar||−713 – −712|
|Ethiopian calendar||−437 – −436|
|- Vikram Samvat||−373 – −372|
|- Shaka Samvat||N/A|
|- Kali Yuga||2672–2673|
|Iranian calendar||1051 BP – 1050 BP|
|Islamic calendar||1083 BH – 1082 BH|
|Minguo calendar||2341 before ROC
|Thai solar calendar||113–114|
|Wikimedia Commons has media related to 430 BC.|
Year 430 BC was a year of the pre-Julian Roman calendar. At the time, it was known as the Year of the Consulship of Crassus and Iullus (or, less frequently, year 324 Ab urbe condita). The denomination 430 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 army of Sparta loots Attica for a second time, but Pericles is not daunted and refuses to revise his initial strategy. Unwilling to engage the Spartan army in battle, he again leads a naval expedition to plunder the coasts of the Peloponnesus, this time taking 100 Athenian ships with him.
- Potidaea finally capitulates to the siege by Athenian forces in the winter.
- An outbreak of a plague hits Athens and the disease ravages the densely packed city (modern DNA analyses of material from ancient cemeteries suggest the mortal disease may have been typhus). The plague wipes out over 30,000 citizens, sailors and soldiers as well as Pericles' two sons. Roughly one quarter of the Athenian population dies. The fear of plague is so widespread that the Spartan invasion of Attica is abandoned, their troops being unwilling to risk contact with the diseased enemy.
- Pericles becomes ill from the plague but he recovers, temporarily. He is deposed from his position as General (or Strategos), but is later reappointed.
Oedipus the king was first performed in Athens
- Empedocles, Greek philosopher (approximate date) (b. c. 490 BC)
- Phidias, Greek sculptor (approximate date) (b. c. 480 BC)
- Zeno of Elea, Greek philosopher (approximate date) (b. c. 490 BC)