When Xuthus emerges from the temple, he is overjoyed, and he greets Ion as his son. Ion, confused, pushes Xuthus away, claiming that he is nothing more than an unknown foreigner. Xuthus explains that, when he was in the sanctuary, the god told him that the next person he saw would be his son.

Ion asks whether Xuthus ever had a lover before his wife, to which Xuthus responds that he has. Ion and Xuthus determine that the latter did indeed consort with maenads (female followers of Dionysus, god of wine and festivity, among other things) at a festival of Bacchus many years ago. They conclude one of these women must have fallen pregnant with his child, which she later exposed. Ion privately expresses interest in knowing his mother.The chorus admits that they, as Athenians, are also invested in Creusa’s fate.

Ion also privately admits his misgivings about living in Athens with Xuthus. First, he fears that he will be ostracized for being a foreigner born out of wedlock. He also fears his birth mother will resent him should he earn fame in Athens. Finally, Ion expresses his happiness living in the sanctuary, where he enjoys tranquility.

Xuthus reassures Ion that his life will be equally happy in Athens, and furthermore, that he will hold a celebratory banquet for his son in Delphi before departing.