The rap veteran was reportedly found unconscious near his home in Beverly Hills and admitted to a hospital in Los Angeles, where he was pronounced dead.
His passing has sent shockwaves through the hip-hop world and a host of stars have taken to their Twitter.com blogs to express their grief at the tragic news.
Nas writes, "RIP TO A REAL HIP HOP LEGEND HEAVY D!", while Common tweets, "Heavy D was...no...is one of Hip-Hops (sic) finest. Your art and contribution will live 4ever (sic) brother! RIP Heavy D".
A stunned Q-Tip writes, "This can't be true", and The Roots drummer ?uestlove adds, "Heavy D was a good friend & he'll be missed."
Rap mogul Russell Simmons states, "I am deeply saddened by the sudden loss of Heavy D. A long time friend and a beautiful person", and Sean Kingston calls him "One Of The Most Influential Rappers Of The '90s Era."
Even Hollywood was mourning the loss of the rapper, who made a handful of movie appearances - actor Samuel L. Jackson called him a "dear friend", adding "Fond memories of a truly cool brutha (sic)."
Heavy D had just returned from a trip to London, where he hung out with British singer Estelle and R&B star Ne-Yo.
A shocked Estelle tweets, "RIP. Heavy D. i can't believe that. I can't. Was just in London w (with) him", while Ne-Yo adds, "Man. I was just with Heavy D recently in London. Had I known it'd be the last time I'd see him, I woulda (sic) told him he was truly great."
A slew of other hip-hop stars, including hitmaker/producer Pharrell Williams, veteran hip-hop DJ Grandmaster Flash, R&B singer Brandy and rapper Nelly have also expressed their condolences online.
Meanwhile, Public Enemy star Chuck D insists his friend was "a hip hop god", adding, "He will always be remembered and I'm thankful for what he's done for hip hop culture."
Heavy D & The Boyz performing Now That We Found Love