|Millennium:||1st millennium BC|
|Centuries:||5th century BC – 4th century BC – 3rd century BC|
|Decades:||380s BC 370s BC 360s BC – 350s BC – 340s BC 330s BC 320s BC|
|Years:||358 BC 357 BC 356 BC – 355 BC – 354 BC 353 BC 352 BC|
|355 BC by topic|
|Gregorian calendar||355 BC|
|Ab urbe condita||399|
|Ancient Egypt era||XXX dynasty, 26|
|- Pharaoh||Nectanebo II, 6|
|Ancient Greek era||106th Olympiad, year 2|
|Chinese calendar||乙丑年 (Wood Ox)
2342 or 2282
— to —
丙寅年 (Fire Tiger)
2343 or 2283
|Coptic calendar||−638 – −637|
|Ethiopian calendar||−362 – −361|
|- Vikram Samvat||−298 – −297|
|- Shaka Samvat||N/A|
|- Kali Yuga||2747–2748|
|Iranian calendar||976 BP – 975 BP|
|Islamic calendar||1006 BH – 1005 BH|
|Minguo calendar||2266 before ROC
|Thai solar calendar||188–189|
|Wikimedia Commons has media related to 355 BC.|
Year 355 BC was a year of the pre-Julian Roman calendar. At the time, it was known as the Year of the Consulship of Peticus and Poplicola (or, less frequently, year 399 Ab urbe condita). The denomination 355 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.
- King Artaxerxes III of Persia forces Athens to conclude a peace which requires the city to leave Asia Minor and to acknowledge the independence of its rebellious allies.
- King Archidamus III of Sparta supports the Phocians against Thebes in the "Sacred War".
- Chares' war party in Athens is replaced by one under Eubulus which favours peace. Eubulus restores the economic position of Athens without increasing the burden of taxation and improves the Athenian fleet while its docks and fortifications are repaired.
- Xenophon, Greek historian, soldier, mercenary and an admirer of Socrates (b. c. 431 BC)
- Eudoxus of Cnidus, Greek astronomer and mathematician (b. c. 408 BC)