"Beautiful Dreamer" is a song by Stephen Foster written about 1862. It was first published (posthumously) in 1864 by William A. Pond & Co. It has been promoted as Foster's last song, but that distinction cannot be confirmed. It is similar in some respects to his first published song, "Open They Lattice, Love". Both have a triple rhythm and share imagery of the sea and marine life.
The arpeggiated accompaniment recalls bel canto opera. The dreamer in this song is either asleep or dead. The song does not distinguish. It is a song though about dissolution — of melting, of dissolving, of vanishing into mists, and, finally into death. The song is not held in the highest esteem by some musicologists and has been described by one as "saccharine" and "[smacking] somewhat of the idiom of Irving Berlin."