According to current discipline classification, folk literature is usually categorized as an individual research field, distinguished from classical literature or classical canon, which leads to the fact that in current research, the study of folk literature is often separated from the study of classical texts, or even opposed to it. This paper intends to review the relations and relationships between the two and argues that, at least, in ancient Greek world of culture, there is a considerable intersection between folk literature and classical literature. In many cases, a myth appeared both in the two literary fields, and thus these two fields were often intertwined and in conversation. Taking Athenian autochthony as a case study, this paper shows that this myth not only appeared as a folk story in daily occasions such as symposium, architecture, and vase painting, but also entered classic texts such as the tragic works of the three great tragedians and even Plato’s philosophical works, becoming one part of “classical literature”. By examining the application of the myth in folk literature and classical literature, it can be seen that in ancient Greece, folk and classical literature not only communicated and borrowed from each other, but also formed a dialogue between the two, thus constructing a lively and living literary world.