The theme song for Leverage, as per other previous claims, is not “Mercy” by Duffy. Sure, “Mercy” was used for Leverage promotional material and commercials, but is definitely not the theme song, nor the one used in the show’s opening credits.
The show only started to have a short opening credits with background music, the one where Nathan Ford (Timothy Hutton) says “The rich and powerful, they take what they want…” in season 2, but that exact same piece was used in the pilot episode of season 1.
The only information I have as of present time about the show’s original theme music is that is was composed Joseph LoDuca, an award-winning television and film score composer.
Watch & Listen
There is another recurring theme from this show which is always played when they are currently setting up a job. It is this bass-driven song with a cool melody. If you know what I am talking about and actually know information about it, please hit the comments.