Bad est une chanson de Michael Jackson, écrite et composée par Michael Jackson, sortie le 7 septembre 1987. Second single extrait de l'album Bad, il se classa no 1 au Billboard Hot 100, aux Hot R&B/Hip-Hop Songs, aux Hot Dance Club Songs2 et dans plusieurs hit-parades européens.

Le morceau était à l'origine prévu comme un duo avec Prince, longtemps considéré dans les médias comme LE "rival" de Michael Jackson. Quincy Jones, dans une interview incluse dans la réédition 2001 de Bad, raconte que Prince aurait dit à Michael Jackson qu'il ne voulait pas y participer, précisant par délicatesse que, le titre étant de Michael Jackson, il serait un tube, même sans lui. Selon un entourage proche de Prince, il aurait plaisanté en disant la refuser parce que la chanson démarre par « Ton cul est mien » (« Your butt is mine »), et il n'aurait simplement pas aimé le morceau.

Your butt is mine, gonna tell you right
Just show your face in broad daylight
I'm telling you on how I feel
Gonna hurt your mind, don't shoot to kill
Come on, come on
Lay it on me, all right
I'm giving you on count of three
To show your stuff or let it be
I'm telling you just watch your mouth
I know your game what you're about

[Pre-Chorus]
Well they say the sky's the limit
And to me that's really true
But my friend you have seen nothing
Just wait til I get through

[Chorus]
Because I'm bad, I'm bad (Shamone, really, really bad)
You know I'm bad, I'm bad
You know it (really, really bad)
You know I'm bad, I'm bad (Shamone)
You know (really, really bad)
And the whole world has to
Answer right now
Just to tell you once again:
Who's bad?

[Verse 2]
The word is out, you're doing wrong
Gonna lock you up before too long
Your lying eyes gonna tell you right
So listen up, don't make a fight
Your talk is cheap, you're not a man
You're throwing stones to hide your hands

[Pre-Chorus]
Well they say the sky's the limit
And to me that's really true
But my friend you have seen nothing
Just wait til I get through

[Chorus]
Because I'm bad, I'm bad (Shamone, really, really bad)
You know I'm bad, I'm bad
You know it (really, really bad)
You know I'm bad, I'm bad (Shamone)
You know (really, really bad)
And the whole world has to
Answer right now
Just to tell you once again:
Who's bad?

[Pre-Chorus]
We can change the world tomorrow
This could be a better place
If you don't like what I'm saying
Then won't you slap my face?

[Chorus]
Because I'm bad, I'm bad (Shamone, really, really bad)
You know I'm bad, I'm bad
You know it (really, really bad)
You know I'm bad, I'm bad (Shamone)
You know (really, really bad)
And the whole world has to
Answer right now
Just to tell you once again:
Who's bad?