In Greek mythology, Catreus (Katreus, English translation: "down-flowing") was a king of Crete and a son of Minos and Pasiphaë. He had one son, Althaemenes, and three daughters, Apemosyne, Aerope and Clymene. Catreus was mistakenly killed by his son thereby fulfilling an oracle.
Pausanias, 8.53.4 says that while the Cretans claim Catreus was the son of Minos, that according to the Tegeans, Catreus was the son of Tegeates. According to this tradition, Catreus may have been the ruler of the ancient Cretan city Katri, now Kandanos.
According to Apollodorus' account, an oracle told Catreus that one of his children would kill him. Although Catreus kept the prophecy secret, his son Althaemenes found out, and fearing that he would kill his father, took his sister Apemosyne and left Crete for Rhodes. Catreus gave his other daughters to Nauplius to be sold off in foreign lands: Aerope married Pleisthenes, and Clymene married Nauplius. Years later, Catreus sailed the seas searching for his son, the heir to the throne. His ship stopped at Rhodes and was mistaken for a pirate ship. Althaemenes and others attacked the 'invaders', and the prophecy came to pass; Catreus died at the hands of his son, from a javelin blow. Diodorus Siculus, gives a slightly different version of the story, saying that an oracle had been given to Althaemenes which said that he was destined to kill his father. Another tradition, followed by Sophocles in his play Ajax and by Euripides in the lost play Kressai, was that Catreus found Aerope in bed with a slave and sent her to Nauplius to be drowned.
The story of Catreus shares similarities with stories told about Aleus, king of Tegea. In these stories, Aleus received an oracle that his grandson would kill Aleus' sons, so Aleus took measures to keep his daughter Auge a virgin, nevertheless Auge became pregnant (by Heracles) and Aleus (as did Catreus) gives his daughter to Nauplius, to be drowned but instead Nauplius sold her to the Mysian king Tethras, who adopts her son Telephus, as his heir. As an adult Telephus returns to Tegea and unknowingly kills his uncles.
According to Apollodorus, Menelaus, Aerope's son, was away at Catreus' funeral, when Paris took Helen to Troy.