"You'll Be Back" is the seventh song from Act 1 of the musical "Hamilton", based on the life of Alexander Hamilton, which premiered on Broadway in 2015. Lin-Manuel Miranda wrote both the music and lyrics to the song. It is sung by Jonathan Groff in the show's original cast recording.
The song was first performed by Groff.
The original cast recording had him performing the song, so he would have been the original performer.