Lance Reddick's cause of death has been revealed as heart disease ... according to the late actor's death certificate.

The document, obtained by TMZ, lists Reddick's immediate cause of death as Ischemic Heart Disease as well as Atherosclerotic Coronary Artery Disease. The death cert also states Reddick was to be cremated.

TMZ broke the story ... Reddick, best known for his role in "The Wire" and the 'John Wick' movie franchise,was found dead at his Studio City home on March 17. At the time, law enforcement sources said his death appeared to be of natural causes.

We know Lance's wife,Stephanie, was the one who dialed 911 after finding him collapsed in the backyard.

Just before he died, Lance was doing a press tour for the "John Wick: Chapter 4" film ... and he even had an appearance scheduled onKelly Clarkson's show for the week after he passed away.

Lance posted a selfie video just days before his sudden death at home with his pups, raising questions as to why he wasn't attending the 'Wick 4' premiere in New York City.

Lance's castmateshonored him by wearing blue ribbons to the movie's premiere in Los Angeles, andKeanu Reeves shared some touching words about his friend.

Outside of 'John Wick,' Lance was also famous for his work in HBO's "The Wire" where he played Baltimore Police Department officer Cedrick Daniels in all 5 seasons of the show.

Throughout his career he racked up a ton of credits including shows like "Fringe," "Bosch," "Oz" and "Lost" ... he also appeared in films such as "Angel Has Fallen" and "Godzilla Vs. Kong."

Lance was 60.

RIP