The Baghdad Battery is an ancient artifact, discovered near Baghdad, Iraq, consisting of a clay jar, a copper cylinder, and an iron rod. It is sometimes described as an ancient battery, because a similar arrangement could potentially produce a small electrical voltage when filled with an acidic liquid. However, there is no conclusive evidence that it was actually used as a battery. It is generally dated to around the first few centuries BCE/CE and is associated with the Parthian or Sasanian period.

The Baghdad Battery is believed to be about 2000 years old. The jar was found in Khujut Rabu just outside Baghdad and is composed of a clay jar with a stopper made of asphalt. Sticking through the asphalt is an iron rod surrounded by a copper cylinder.