"Trees" is a lyric poem by American poet Joyce Kilmer. Written in February 1913, it was first published in Poetry: A Magazine of Verse that August and included in Kilmer's 1914 collection Trees and Other Poems. The poem, in twelve lines of rhyming couplets of iambic tetrameter verse, describes what Kilmer perceives as the inability of art created by humankind to replicate the beauty achieved by nature.

Kilmer is most remembered for "Trees", which has been the subject of frequent parodies and references in popular culture. Kilmer's work is often disparaged by critics and dismissed by scholars as being too simple and overly sentimental, and that his style was far too traditional and even archaic. Despite this, the popular appeal of "Trees" has contributed to its endurance. Literary critic Guy Davenport considers it "the one poem known by practically everybody". "Trees" is frequently included in poetry anthologies and has been set to music several times—including a popular rendition by Oscar Rasbach, performed by singers Nelson Eddy, Robert Merrill, and Paul Robeson.

The location for a specific tree as the possible inspiration for the poem has been claimed by several places and institutions connected to Kilmer's life; among these are Rutgers University, the University of Notre Dame, and towns across the country that Kilmer visited. However, Kilmer's eldest son, Kenton, declares that the poem does not apply to any one tree—that it could apply equally to any. "Trees" was written in an upstairs bedroom at the family's home in Mahwah, New Jersey, that "looked out down a hill, on our well-wooded lawn". Kenton Kilmer stated that while his father was "widely known for his affection for trees, his affection was certainly not sentimental—the most distinguished feature of Kilmer's property was a colossal woodpile outside his home".