Kings of Iolcus

thumb|Pelias sends forth Jason, in an 1879 illustration from Stories from the Greek Tragedians by Alfred Church.

In Greek mythology, Aeson (; Ancient Greek: Αἴσων Aísōn) was a king of Iolcus in Thessaly. He was the father of the hero Jason. According to one version of the story, he was imprisoned by his half-brother Pelias, and when Pelias intended to kill him he committed suicide. In another story, he was killed by Jason's wife Medea, who brought him back to life as a young man.

Acastus (; ) is a character in Greek mythology. He sailed with Jason and the Argonauts, and participated in the hunt for the Calydonian Boar.