Death is absolutely a primary theme in Sylvia Plath's "Daddy." Otto Plath, Sylvia Plath's father, died when when she was eight years old (though in the poem she states that "I was ten when they buried you"). This event is thought to have had a profound effect on Plath, and Otto Plath is thought to be the subject of the poem.

The entire poem is based around the concept of death and how later context can change our perspective of it. To the speaker, her father is a "god" when he is buried, his body stretching from sea to sea. A decade later, she attempts suicide in order to get back to him. The speaker seems almost wistful and sad describing how she was stopped from doing this. She approaches life thereafter with resignation.

However, the poem is book-ended with a powerful announcement that the speaker will no longer be trapped in the memory of her father. This poem was written shortly after Plath's divorce from her husband, and in the poem, it is evidenced that she tried to bring her father back into her life by marrying a "brute like him." After banishing her parasite of a husband, she realizes that she can finally exorcise the ghost of her father in a way that she never could before. This moment is captured with the powerful final line "Daddy, daddy, you bastard, I'm through."