"When I Have Fears" is an Elizabethan sonnet by the English Romantic poet John Keats. The 14-line poem is written in iambic pentameter and consists of three quatrains and a couplet. Keats wrote the poem between 22 and 31 January 1818. It was published (posthumously) in 1848 in Life, Letters, and Literary Remains, of John Keats by Richard Monckton Milnes.