Charles is of Italian descent and,[7] the son of Chucky and Mary Rosa was born and raised in Peabody, Massachusetts.[8] Rosa's father, grandfather, and uncle were all professional boxers. Rosa had two older brothers, Domenic and Vincent, who both died from accidental drug overdoses.[9] He also has a sister, Teresa, and two younger brothers, Lucas and Francis.[9] Growing up, Rosa played football, hockey, lacrosse, and also trained in karate.Rosa continued playing lacrosse at Johnson & Wales University, where he also earned a degree in the culinary arts. After graduating from the college, Rosa later relocated to Florida to find a fresh start.[9] Looking for a boxing gym, Rosa stumbled upon American Top Team gym, where he began to train in mixed martial arts.