Zak Williams, 36, and his fiancée, Olivia June, welcomed a son in May, who they named after the comedic actor who died in August 2014.
McLaurin Clement Williams was born on May 22, People reported. "McLaurin" was Williams' middle name. The pair intends to call their baby "Mickey," for short.
In a 2014 interview with the news outlet, Zak Williams said of his father: “I miss him all the time."
“Often I see something or if I’m watching a film, I think, ‘Oh, man, he would have appreciated this’ or ‘He would have gotten a laugh out of this,'" the actor's oldest child said.
The Oscar winner, who had three children — Zak, Zelda, 29, and Cody, 27 — died nearly five years ago at 63. He was known for his wide-ranging roles in dramas and comedies in his four-decade-long career, that led to four Academy Award nominations and a win for "Good Will Hunting."
The Associated Press contributed to this report.