Year 439 BC was a year of the pre-Julian Roman calendar. At the time, it was known as the Year of the Consulship of Lanatus and Barbatus (or, less frequently, year 315 Ab urbe condita). The denomination 439 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.

• As a result of Persian assistance to Samos, it takes the Athenian army nine months to successfully complete its siege of Samos and force the Samians to surrender. Samos becomes a tributary of Athens.^[1]

• Spurius Maelius, a wealthy Roman plebeian, tries to buy popular support with the aim of making himself king. During the severe famine affecting Rome, he buys up a large store of grain and sells it at a low price to the people of Rome – the first time this had been done in Rome. This leads Lucius Minucius, the patrician praefectus annonae ("president of the market"), to accuse Maelius of seeking to take over the government.^[2]
• Lucius Quinctius Cincinnatus is made dictator of the Roman Republic for a second time to deal with the Maelius controversy. He appoints Gaius Servilius Ahala as his Master of the Horse.^[3]

• Maelius is summoned before Cincinnatus but refuses to appear. Shortly thereafter, Maelius is killed by Gaius Servilius Ahala and his house is burnt to the ground.^[4][5]

• Spurius Maelius - was the youngest man to ever attempt taking over Rome