Shakespeare's sonnets are a collection of 154 sonnets dealing with the themes of love, beauty and mortality. Almost all of the sonnets are constructed from three four-line stanzas (or quatrains) and a final couplet composed in iambic pentameter. Over the course of the sonnets, three characters emerge, who are: the Fair Youth, the Rival Poet and the Dark Lady. The speaker admires the Youth's beauty and has an affair with the Dark Lady. The Fair Youth is addressed in sonnets 1-126, the Dark Lady in sonnets 127-152 and the Rival Poet in sonnets 78-86.

Of all of Shakespeare's sonnets, sonnet 18, or 'Shall I compare thee to a summer's day' is probably best known to English-speaking audiences.