Aulus Postumius Tubertus was a Roman commander in the war with Aequi and Volsci in the 5th century BCE. He was magistrem equitum under dictator Mamercus Emilius Mamercinus in 433 BCE.
Postumius was the son-in-law of Titus Quinctius Cincinnatus Pennus, consul in 431 and 428 BCE. When it was decided to call a dictator to undertake war with Aequi and Volsci in 431 BCE, the consuls did not agree on the choice of Postumius, so the choice fell on Cincinnatus, who was nominated as a dictator. Cincinnatus and Postumius entered the war with the enemy, and on June 18, 431 BCE they won a great victory over Aequi and Volsci on Mount Algidus. This was the place of the previous victory over the Aequi by dictator Lucius Quincius Cincinnatus in 458 BCE. The battle of Mount Algidus was the last major battle between Rome and Aequi.
Upon his return, Postumius was given the right to have a triumph. There is a story associated with this battle. During this campaign, Postumius’s son was so eager to fight the enemy that he abandoned the post assigned to him by his father. Consequently, Postumius sentenced him to death. Livy, however, doubts the truth of this story, noting that a similar story was associated with Titus Manlius Torquatus, consul in 347, 344 and 340 BCE and his son.