Antipater I the Idumaean (born 113 or 114 BCE, died 43 BCE) was the founder of the Herodian Dynasty and father of Herod the Great. According to Josephus, he was the son of Antipas and had formerly held that name.

A native of Idumaea, a region southeast of Judah in which the Edomites settled during the classical period, Antipater became a powerful official under the later Hasmonean kings and subsequently became a client of the Roman general Pompey the Great when Pompey conquered Judah in the name of Roman Republic.

When Julius Caesar defeated Pompey, Antipater rescued Caesar in Alexandria, and was made chief minister of Judea, as Judah became known to the Romans, with the right to collect taxes. Antipater eventually made his sons Phasaelus and Herod the governors of Jerusalem and Galilee, respectively. After the assassination of Caesar, Antipater was forced to side with Gaius Cassius Longinus against Mark Antony. The pro-Roman politics of Antipater led to his increasing unpopularity among the devout, non-Hellenised Jews. He died by poison.

The diplomacy and artful politics of Antipater, as well as his insinuation into the Hasmonean court, paved the way for the rise of his son Herod the Great, who used this position to marry the Hasmonean princess Mariamne, endear himself to Rome and become king of Judea under Roman influence.