Lamia is a narrative poem written by John Keats. It was published in 1820. The poem's overarching theme is Greek mythology. Many of the Romantic-era poets, such as John Keats, used Greek mythology as a trope for their poetic works.

The titular character, Lamia, is the central figure of the poem. Hermes, who was looking for a beautiful nymph, finds Lamia in the form of a serpent. This anthropomorphic theme is common in Greek mythology stories, and the duality of the deity-beast, or mortal-beast, symbolizes the dual nature of humans; even gods and goddesses, who represent the virtues of humans, have bestial qualities.

When Lamia reveals the invisible nymph that Hermes was trying to find, he returns the favor to Lamia by transforming her back to her human form. The other theme of the poem is the tragic ending to a love affair. When Lamia returns to her lover, Lycius, all seems well again. However, when Apollonius reveals Lamia's true nature, she disappears, and Lycius dies grieving her loss.

The theme of tragedy is one of the commonalities between the Romantic poets and Greek mythology. John Keats himself experienced romantic relationships that did not work out, and using the tragedies of mythology, he was able to dramatize the emotions he felt in real life.