|Millennium:||1st millennium BC|
|Centuries:||6th century BC – 5th century BC – 4th century BC|
|Decades:||470s BC 460s BC 450s BC – 440s BC – 430s BC 420s BC 410s BC|
|Years:||450 BC 449 BC 448 BC – 447 BC – 446 BC 445 BC 444 BC|
|447 BC by topic|
|Gregorian calendar||447 BC|
|Ab urbe condita||307|
|Bahá'í calendar||−2290 – −2289|
|English Regnal year||N/A|
|Chinese calendar||癸巳年 (Water Snake)
2250 or 2190
— to —
甲午年 (Wood Horse)
2251 or 2191
|Coptic calendar||−730 – −729|
|Ethiopian calendar||−454 – −453|
|- Vikram Samvat||−390 – −389|
|- Shaka Samvat||N/A|
|- Kali Yuga||2655–2656|
|Igbo calendar||−1446 – −1445|
|Iranian calendar||1068 BP – 1067 BP|
|Islamic calendar||1101 BH – 1100 BH|
|Minguo calendar||2358 before ROC
|Thai solar calendar||97|
|Wikimedia Commons has media related to 447 BC.|
Year 447 BC was a year of the pre-Julian Roman calendar. At the time, it was known as the Year of the Consulship of Macerinus and Iullus (or, less frequently, year 307 Ab urbe condita). The denomination 447 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.
- Pericles leads Athenian forces in the expulsion of barbarians from the Thracian peninsula of Gallipoli, in order to establish Athenian colonists in the region. Thus Pericles starts a policy of kleruchos or "out-settlements". This is a form of colonisation where poor and unemployed people are assisted to emigrate to new regions.
- A revolt breaks out in Boeotia as the oligarchs of Thebes conspire against the democratic faction in the city. The Athenians, under their general Tolmides, with 1000 hoplites plus other troops from their allies, march into Boeotia to take back the towns revolting against Athenian control. They capture Chaeronea, but are attacked and defeated by the Boeotians at Coronea. As a result, the Athenians are forced to give up control of Boeotia as well as Phocis and Locris, which all fall under the control of hostile oligarchs who quit the Delian League.
- The middle component of the Long Walls from Athens to the port city of Piraeus is completed.
- Pericles commissions the architects Kallikrates and Iktinos to design a larger temple for the Parthenon and the construction begins on rebuilding the great temple of Athena (the Parthenon) on the Acropolis at Athens soon afterwards.