This was featured in the 1961 Elvis movie Blue Hawaii. According to songwriter George Weiss, neither the movie producers nor Elvis' associates liked the song demo. Elvis insisted on recording this song for the movie.
The melody is based on a French song called "Plaisir D'Amour."
For more facts & trivia on "Can't help Falling in Love" go to http://www.songfacts.com/detail.php?id=1159.