The Cistern of Aetius (Κινστέρνα του Αετίου) was a huge open-air water reservoir in Byzantine Constantinople. It is near the Theodosian Walls, around 300 meters east of the Gate of Charisius (Edirnekapı). It was originally located along the northern branch of the Mese and shared the same water supply line as the Aqueduct of Valens. It seems that the cistern was built by Aetius (Aetios) in 421, who served as the eparch of Constantinople in 419. In the past, it was often incorrectly identified with the cistern of Bonus or Aspar. It is also suggested that it might be the cistern that Pulcheria played a role in building, though it is generally accepted that this is the cistern built by Aetius.

The open-air cistern is around 244 x 85 meters with a depth of around 13-15 meters, while its brick and ashlar walls measured 5.2 meters. It had a capacity of as much as 300,000 cubic meters. By the 16th century it was used as a garden, which can be seen in its Turkish name Çukurbostan (“sunken garden”). In 1962, after being used as a sports field for many years, a stadium was built inside the cistern.