Mr. Williams was celebrated for delivering nuanced performances as swaggering street toughs, charming family men and smooth-talking gangsters. He played bootlegger Chalky White on the Prohibition-era HBO series “Boardwalk Empire” and earned four Emmy nominations as a supporting actor, most recently for playing an abusive, alcoholic father in HBO’s “Lovecraft Country.”
But he remained best known for his starmaking, morally ambiguous role in “The Wire,” a gritty portrait of Baltimore crime and corruption that aired on HBO for five seasons beginning in 2002. The shotgun-wielding Omar was supposed to appear in only a few episodes of the show’s first season but became one of the show’s defining characters, known for his strict code of ethics.
“He was more than somebody who went around killing people. He had morals, he had character, he was honest,” Mr. Williams told Canada’s National Post newspaper. “Omar said what he did, and he did what he said. That’s a rarity in human society.”
Mr. Williams was working at his mother’s day-care center, his acting career floundering, when he was cast as Omar. He had seen echoes of his upbringing in the character, although when a prop person handed him a shotgun during his first day on the set, Mr. Williams “didn’t know which end was which,” showrunner and “Wire” creator David Simon told the New York Times in 2017. “Mike is a beautiful man, but a gangster he is not.”
A few days later, Mr. Williams went home to the East Flatbush section of Brooklyn, where he found a drug dealer who taught him the intricacies of firearms while shooting pellets into a steel door on the roof of the Vanderveer Estates, the housing complex where he had grown up. “Best acting lesson I ever had,” he said.
As played by Mr. Williams, Omar was a study in contrasts: a coldblooded killer (“If you come at the king, you best not miss”) who also nuzzles his boyfriend, goes to church and peppers his speech with words like “constabulating.”
Mr. Williams said the lines between him and his character “got blurred” as the show progressed. Acquaintances in his neighborhood started calling him Omar, and while grappling with his own identity he turned to cocaine. He lived out of a suitcase and sometimes came to work high.
“When I wear these characters to the extent that I wear them to, that [energy’s] gotta go somewhere,” he told NPR in 2016. The energy of Omar, he said, “was a little too close to home.” He found help at a Baptist church in Newark — and, by his account, from a meeting with then-Sen. Barack Obama, who declared that Omar was his favorite character on his favorite show.
Mr. Williams continued to deliver acclaimed performances in shows such as “The Night Of” (2016), in which he earned another Emmy nomination for playing a Rikers Island inmate, and “When We Rise” (2017), as gay rights activist Ken Jones, who battled HIV. He drew on his own life for both parts — a nephew had been incarcerated at Rikers, and another had HIV — but said that after his experience on “The Wire,” he had learned “how to differentiate myself from the character.”
“I still go in just as deep,” he told NPR, “but now I have the tools . . . to pull myself out.”
The youngest of 10 children, Michael Kenneth Williams was born in Brooklyn on Nov. 22, 1966. His mother came from the Bahamas and worked as a seamstress, and his parents separated when he was young.
Mr. Williams said he was molested as a boy and struggled with low self-esteem. He dropped out of high school and developed a drug addiction, but also found a sense of community while dancing at New York clubs such as the Roxy and Sound Factory. By his early 20s, he was working as a model and dancer, performing alongside artists including Missy Elliott, George Michael and Madonna.
Just before his 25th birthday, he stepped outside a bar to find a group of men robbing one of his friends. When he tried to stop the attackers, a man slashed his face with a razor blade, leaving a scar from his forehead to right cheek. “Things changed immediately after that,” he told NPR in 2014. “Directors didn’t want me just to dance in the videos any more. They wanted me to act out these thug roles.”
He made his movie debut as the younger brother of Tupac Shakur’s character in “Bullet” (1996), a crime drama, and later appeared as a drug dealer in director Martin Scorsese’s “Bringing Out the Dead” (1999). Later came appearances in episodes of “The Sopranos,” “CSI: Crime Scene Investigation,” “Law & Order” and the sitcom “Community,” in which he played a no-nonsense community college instructor who had spent time in prison.
Information on survivors was not immediately available.
Mr. Williams also appeared in movies including “Gone Baby Gone” (2007), “The Road” (2009) and “12 Years a Slave” (2013), and starred opposite James Purefoy in the dark comedy series “Hap and Leonard” (2016-2018).
He received his other Emmy nominations for the TV movie “Bessie” (2015), as the husband of singer Bessie Smith, and “When They See Us” (2019), as the father of Antron McCray, one of five teenagers wrongly accused of attacking a Central Park jogger in 1989. He also moved into film and television production in recent years, and shared an Emmy nomination in 2018 as an executive producer of the documentary series “Vice.”
Mr. Williams said he was aiming to tell more stories that reflected the community where he was raised. “Vanderveer is 59 buildings, six floors high, with seven apartments on each level,” he told the Times, referring to his old home. “There are so many people here — beautiful and beautifully flawed people — and I want all of their stories to be told.”
Travis M. Andrews contributed to this report.