Colin Leonard is an American mastering engineer. His credits include: Alessia Cara, Justin Bieber, Jay-Z, Bryson Tiller, Echosmith, Leona Lewis, Migos, Icona Pop, Mastodon, Kimbra, Indigo Girls and Gucci Mane to name a few. Sales of albums and singles sold in the US with Colin Leonard listed in the credits as a mastering engineer total over 100 million.