In Greek mythology, Aerope (Ancient Greek: Ἀερόπη) was a Cretan princess as the daughter of Catreus, king of Crete. She was the sister of Clymene, Apemosyne and Althaemenes. After an oracle said he would be killed by one of his children, Catreus gave Aerope to Nauplius to be sold abroad. Nauplius spared her, and she became the wife of Atreus or Pleisthenes (or both). By most accounts, she is the mother of Agamemnon and Menelaus. While the wife of Atreus, she became the lover of his brother Thyestes, and gave Thyestes the golden lamb that allowed him to become king of Mycenae.

Aerope's father was Catreus, son of Minos, and king of Crete. Catreus had two other daughters, Clymene and Apemosyne, and a son, Althaemenes.

In most accounts, Aerope was the mother of Agamemnon and Menelaus, fathered by Atreus. However, their father is occasionally named as Pleisthenes. In other retellings, Aerope was instead the mother of Pleisthenes by Atreus. When Pleisthenes died young, his sons, Agamemnon and Menelaus, were adopted by Atreus. In others, Aerope was the wife of both Atreus and Pleisthenes, having married Atreus after Pleisthenes died, with Atreus adopting her children from the first marriage. Such accounts were perhaps attempts to reconcile separate traditions.

According to Hyginus, Aerope was the mother of two sons, Tantalus and Pleisthenes, fathered by Thyestes. He claims these were the children that Atreus famously fed to Thyestes. Additionally, Aerope has also been named as the mother of a daughter, Anaxibia.

According to the tradition followed by Euripides in his lost play Cretan Women (Kressai), Catreus found Aerope in bed with a slave and handed her over to Nauplius to be drowned. Instead, Nauplius spared Aerope's life and she married Pleisthenes. Sophocles, in his play Ajax, may also refer to Aerope's father finding her in bed with a man and handing her over to Nauplius to be drowned. However, the potentially corrupt text may instead refer to Aerope's husband Atreus finding her in bed with Thyestes, and having her drowned (see below).

The mythographer Apollodorus followed a different tradition, with no mention of any sexual transgression. In his account, Catreus gave Aerope and her sister Clymene to Nauplius to be sold off in foreign lands after an oracle prophesied that he would be killed by one of his children. Aerope's brother Althaemenes also found out about the prophecy, and fearing that he would be the one to kill Catreus, fled to Rhodes with Apemosyne. In this telling, Aerope eventually becomes the wife of Pleisthenes.

From Crete, Aerope was taken to Mycenae. There, while the wife of Atreus, she became the lover of Atreus' twin brother Thyestes, involving herself in the brothers' power struggle for the kingship of Mycenae.

Atreus and Thyestes were the sons of Pelops and Hippodamia, king and queen of Pisa. Their desire for their father's throne led to the murder of their half-brother Chrysippus, for which they were banished, and sought refuge in Mycenae. According to Hyginus, the brothers were encouraged to commit the act by their mother Hippodamia, who killed herself upon being accused of doing so. When the Perseid dynasty came to an end, the Myceneans received a prophesy saying they should choose a son of Pelops as their king. Aerope stole the golden lamb (a portent linked to the kingship of Mycenae) from her husband Atreus and gave it to Thyestes, so that the Myceneans would choose Thyestes as their king.