|Millennium:||1st millennium BC|
|Centuries:||6th century BC – 5th century BC – 4th century BC|
|Decades:||520s BC 510s BC 500s BC – 490s BC – 480s BC 470s BC 460s BC|
|Years:||495 BC 494 BC 493 BC – 492 BC – 491 BC 490 BC 489 BC|
|492 BC by topic|
|Gregorian calendar||492 BC|
|Ab urbe condita||262|
|Bahá'í calendar||−2335 – −2334|
|English Regnal year||N/A|
|Chinese calendar||戊申年 (Earth Monkey)
2205 or 2145
— to —
己酉年 (Earth Rooster)
2206 or 2146
|Coptic calendar||−775 – −774|
|Ethiopian calendar||−499 – −498|
|- Vikram Samvat||−435 – −434|
|- Shaka Samvat||N/A|
|- Kali Yuga||2610–2611|
|Igbo calendar||−1491 – −1490|
|Iranian calendar||1113 BP – 1112 BP|
|Islamic calendar||1147 BH – 1146 BH|
|Minguo calendar||2403 before ROC
|Thai solar calendar||52|
|Wikimedia Commons has media related to 492 BC.|
Year 492 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 Augurinus (or, less frequently, year 262 Ab urbe condita). The denomination 492 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 first expedition of King Darius I of Persia against Greece commences under the leadership of his son-in-law and general, Mardonius. Darius sends Mardonius to succeed his satrap (governor) in Ionia, Artaphernes, with a special commission to attack Athens and Eretria.
- The Persians under Mardonius subdue and capture Thrace and Macedonia.
- Mardonius loses some 300 ships in a storm off Mount Athos, which forces him to abandon his plans to attack Athens and Eretria.
- When Camarina, a Syracusan colony, rebels, Hippocrates, the tyrant of Gela, intervenes to wage war against Syracuse. After defeating the Syracusan army at the Heloros River, he besieges the city. However, he is persuaded by the intervention of forces from the Greek mainland city of Corinth to retreat in exchange for the possession of Camarina.
- Following the conclusion of the secession of the plebs, a famine strikes Rome. The consuls avert the crisis by obtaining grain from Etruria.
- War with the Volsci is averted because a pestilence affects the Volsci. Rome sends additional colonists to Velitrae and establishes a new colony in Norba.