He was 69.
TMZ reported the one-time Lucchese crime family associate died Tuesday after a long battle with an undisclosed illness.
"He had been sick for a long time," his girlfriend, Lisa Caserta, told TMZ. "His heart gave out."
The Brooklyn, N.Y., native was accused of extortion, theft, kidnapping, assault, drug dealing and a host of other offenses during his career in organized crime, but he spent his later years working with troubled youth and as a consultant to law-enforcement agencies. He also was an artist, popular guest on Howard Stern's radio show and author of "The Wiseguy Cookbook."
"It took a long time for me to forgive myself," Hill told United Press International in a 2002 telephone interview. "I just try to be one grain of sand better today than I was yesterday. I found my spirituality. I help the kids, young people in trouble."
Reflecting on his long career as a gangster, his decision to end it by testifying against his former associates, and his colorful relationship with the government while in the Federal Witness Protection program, living in places such as Nebraska, Kentucky and Washington state, Hill said he no longer looked over his shoulder for fear one of his former associates will kill him.
Hill, who struggled with addictions to drugs and alcohol for most of his adult life, was ultimately expelled from witness protection because he refused to keep a low profile and kept getting arrested.
"For 10 years, I lived a miserable life, but now there isn't anyone alive that I was involved with ... The people that tried to kill me and my family, that's the only people I knew about and most of them wound up with bullets in their head," Hill explained a decade ago. "I work hard. I'm not on Easy Street by no means, but I'm okay. I live a good life. I try to keep my life simple.
"The stigma of being a rat is hard to live with," he admitted, adding he ultimately found comfort in the thought he actually may have saved lives by helping put away the bad guys.
"That's the way it is," Hill said. "It wasn't glamorized. It showed what it was like."
The rabid fan of "The Sopranos" did, however, condemn films and TV shows that perpetuate the so-called mob mystique, noting being a mobster is more "every man for himself" than "family first" or "honor among thieves."
Asked if it bothered him to watch movies or TV programs that remind him of his former life, Hill replied: "I watch them all ... I don't take that whole life seriously ... I own my past."
He is survived by a son and daughter from his marriage to ex-wife Karen Friedman.