Actor Michael Madsen has died unexpectedly.

One of his managers, Ron Smith, confirmed the news on Thursday, revealing he died from cardiac arrest.

Madsen was 67.

Known for his roles in “Reservoir Dogs,” “Donnie Brasco,” “Thelma & Louise” and “Kill Bill,” Madsen was discovered unresponsive by authorities in his Malibu, California, home early this morning.

He was pronounced dead at the scene at 8:25 a.m., a representative for the Los Angeles County Sheriff’s Department confirmed to The Post, adding that no foul play is suspected.

Madsen’s death is believed to be from natural causes, according to law enforcement.

The actor’s representatives released a statement following his sudden passing.

“In the last two years Michael Madsen has been doing some incredible work with independent film including upcoming feature films ‘Resurrection Road,’ ‘Concessions’ and ‘Cookbook for Southern Housewives,’ and was really looking forward to this next chapter in his life,” his reps — managers Smith and Susan Ferris and publicist Liz Rodriguez — told The Post.

“Michael was also preparing to release a new book called ‘Tears for My Father: Outlaw Thoughts and Poems,’ currently being edited,” they continued. “Michael Madsen was one of Hollywood’s most iconic actors, who will be missed by many.”

Madsen was born in Chicago on Sept. 25, 1957. His sister is “Sideways” actress Virginia Madsen, 63.

His feature film debut came in the 1983 sci-fi techno thriller “WarGames,” but over his four-decade career, he became known for his tough guy roles and as a Quentin Tarantino favorite.

He famously played the cruel criminal Mr. Blonde in Tarantino’s 1992 directorial debut, “Reservoir Dogs,” before starring as Budd in the legendary filmmaker’s “Kill Bill” Volumes 1 and 2 in 2003 and 2004.

Madsen and Tarantino also teamed up for “The Hateful Eight” (2015) and “Once Upon a Time in … Hollywood” (2019).

His “Reservoir Dogs” co-star Harvey Keitel and “Kill Bill” co-star Vivica A. Fox reacted to the news of Madsen’s passing on Thursday.

“We’ve lost another great American poet. Farewell, my dear friend,” Keitel, 86, exclusively told The Post.

“I’ll never forget one of the best scenes I’ve ever seen on film, of you and Chris Penn fighting in ‘Reservoir Dogs.’ A great love scene,” the actor praised Madsen and their co-star Penn, Sean Penn’s brother, who passed away in 2006. “Give Chris a hug for me.”

“I had the pleasure of working with Michael Madsen on ‘Kill Bill’ & several other films!” Fox, 60, told The Post in a statement. “Michael was a talented man with an AMAZING on screen presence! My deepest condolences & prayers to his family. #GoneToSoon #RestInParadise.”

Madsen worked on over 325 projects throughout his career. His last public appearance was at the Chiller Theatre Expo on April 27, a horror convention in New Jersey.

Madsen was also a poet, and he published several volumes. “Tears for My Father: Outlaw Thoughts and Poems” is due out next year.

Tarantino wrote in the foreword for the book: “For me, the real journey that Michael the writer is exploring is what it means to be a man in a world where the notions of manhood that some of us grew up with are barely remembered. But then if everybody embarked on the hero’s journey, everybody would be a hero, wouldn’t they?”

The actor previously opened up about playing so many toughs, claiming, “Fame is a two-edge sword.”

“There are a lot of blessings but also a lot of heavy things that come with it. I think it has a lot to do with the characters I’ve played. I think I’ve been more believable than I should have been. I think people really fear me,” Madsen told the Hollywood Reporter in 2018. 

“They see me and go: ‘Holy s–t, there’s that guy!’ But I’m not that guy. I’m just an actor. I’m a father, I’ve got seven children. I’m married, I’ve been married 20 years. When I’m not making a movie, I’m home, in pajamas, watching ‘The Rifleman’ on TV, hopefully with my 12-year-old making me a cheeseburger. I sure as hell had my rabble-rousing days, but sooner or later you have to get over that and move on,” he continued.

Adding that it’s “part of the whole bad-boy package,” Madsen went on to say, “But I’d rather have a movie like ‘Reservoir Dogs’ than not have it. 

“There are a lot of actors that are a lot more recognized or famous than me, who get paid a lot more than me who haven’t done even one film that you’d remember,” he said. “So I feel blessed and lucky that, that whatever I’ve done, I’ve done a couple of films that will be around for a long time and are respected. And I still get work from them.”

While his career seemed to still be thriving, Madsen’s personal life was recently in shambles.

The star filed for divorce from his third wife, DeAnna Madsen, in September after 28 years of marriage.

Madsen’s decision to end their marriage came two years after their son Hudson’s suicide at the age of 26.

He cited irreconcilable differences as the reason for their split and included a statement as part of the filing in which he blamed DeAnna for their son’s tragic death.

In the statement, Madsen accused her of driving Hudson to suicide “by her neglect, drinking and alcoholism.”

In August of last year, the actor was arrested on a charge of misdemeanor domestic battery. He posted the $20,000 bond, and the LA County District Attorney’s office didn’t file charges due to insufficient evidence, reported TMZ.

“It was a disagreement between Michael and his wife, which we hope resolves positively for them both,” his rep said at the time.

In his divorce documents, Madsen also requested a restraining order against DeAnna.

Madsen is survived by his sisters, Virginia and Cheryl, and his remaining children, including “Divergent” actor Christian Madsen, 35.