An ode is a kind of lyric poetry—which expresses the poet's or speaker's feelings—that praises something, usually something that it directly addresses. In this poem, Keats does praise the season of autumn, directly addressing the season itself using a technique called apostrophe (where the speaker addresses someone or something that is absent or not living as though it were present and alive and could respond). In the first stanza of the poem, the speaker calls the season a close friend of the "maturing sun" because autumn is the season in which all kinds of fruits and vegetables become ripe. The apples "bend" the trees, the gourds "swell," and the hazelnuts grow "plump." Bees continue to enjoy the flowers and make more and more honey. Autumn is abundant in a way that no other season is, and therein lies its beauty.

That theme of abundance and beauty continues into the second stanza, which focuses on the harvest, as the apples are pressed into cider, the grain is milled, and the "fume of poppies" fills the air. Autumn's beauty is further described in the third and final stanza. The speaker compares this season to that of Spring, claiming that Autumn has its own kind of "music," its own beauty in the colors that "bloom the soft-dying day" and the "rosy hue[d]" fields that have been harvested for the year, as well as the sounds created by all the birds and insects. These themes of Autumn's abundance and beauty are apparently throughout the poem.