|Millennium:||1st millennium BC|
|Centuries:||6th century BC – 5th century BC – 4th century BC|
|Decades:||500s BC 490s BC 480s BC – 470s BC – 460s BC 450s BC 440s BC|
|Years:||477 BC 476 BC 475 BC – 474 BC – 473 BC 472 BC 471 BC|
|474 BC by topic|
|Gregorian calendar||474 BC|
|Ab urbe condita||280|
|Bahá'í calendar||−2317 – −2316|
|English Regnal year||N/A|
|Chinese calendar||丙寅年 (Fire Tiger)
2223 or 2163
— to —
丁卯年 (Fire Rabbit)
2224 or 2164
|Coptic calendar||−757 – −756|
|Ethiopian calendar||−481 – −480|
|- Vikram Samvat||−417 – −416|
|- Shaka Samvat||N/A|
|- Kali Yuga||2628–2629|
|Igbo calendar||−1473 – −1472|
|Iranian calendar||1095 BP – 1094 BP|
|Islamic calendar||1129 BH – 1128 BH|
|Minguo calendar||2385 before ROC
|Thai solar calendar||70|
|Wikimedia Commons has media related to 474 BC.|
Year 474 BC was a year of the pre-Julian Roman calendar. At the time, it was known as the Year of the Consulship of Medullinus and Vulso (or, less frequently, year 280 Ab urbe condita). The denomination 474 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.
- Hiero I, tyrant of Sicily, allied with Aristodemus, the tyrant of Cumae, defeat the Etruscan navy in the Battle of Cumae as the Etruscans try to capture the Greek city of Cumae in Italy. This victory marks the end of the Etruscan aggression against the Greeks in southern Italy and saves the Greeks of Campania from Etruscan domination.
- Taranto signs an alliance with Rhegion, to counter the Messapii, Peuceti, and Lucanians, but the joint armies of the Tarentines and Rhegines are defeated near Kailìa (modern Ceglie Messapica).
- Hiero builds Castello Aragonese on the island of Ischia.
- King Xerxes I of Persia issues a decree, as dictated by Mordecai upon the king's secretaries, giving the Jews in every city the authority to unite to defend their lives against their opponents in all of the 127 provinces of the Persian Empire, stretching from India to Ethiopia.
- The Greek poet Pindar moves to Thebes after two years at the Sicilian Court of Hiero I of Syracuse. While at Thebes, he composes lyric odes to celebrate triumphs in the Olympic Games and other athletic events.