"Annie's Song" is a song recorded and written by singer-songwriter John Denver. It was his second number one song in the USA, occupying that spot for two weeks in July 1974. It also went to number one in the UK, where it was Denver's only major hit single (many of Denver's American hits were more familiar in the UK through cover versions by other artists).

"Annie's Song" was written as an ode to Denver's then-wife, Annie Denver (née Martell). Denver "wrote this song in about ten-and-a-half minutes one day on a ski lift" to the top of Bell Mountain in Aspen, Colorado, as the physical exhilaration of having "just skied down a very difficult run" and the feeling of total immersion in the beauty of the colors and sounds that filled all senses inspired him to think about his wife.

The song has since become a wedding standard and an expression of love for many people, due to its grand imagery and the fact it could apply to anyone (Annie is not mentioned by name in any part of the song).

Monty Python did a send-up of the song on their Monty Python's Contractual Obligation Albumin 1980, called "Farewell to John Denver". The track contained a few bars of Eric Idle impersonating John Denver singing "Annie's Song" with joke lyrics: "you came on my pillow..." (followed by the sound of the singer being strangled) and was removed from subsequent pressings of the album on legal advice (reports differ as to whether it had to do with the licensing of "Annie's Song" or the depiction of the popular singer being murdered), and was replaced by an apology spoken by Terry Jones. Later CD releases of the album, however, reinstated the John Denver track.

Its tune is used in the UK by "The Greasy Chip Butty Song", the main chant of fans of Sheffield United football club.