Jon Hamm trolls Landman costar Billy Bob Thornton: 'That man is a national treasure of — what nation, I do not know!'

If you're going to become on-set friends with Jon Hamm, prepare to get roasted.

Speaking with film critic and radio host Elvis Mitchell at the 2025 Sundance Film Festival, Hamm recalled first meeting Landman creator Taylor Sheridan at the 2016 festival, where the Sicario and Hell or High Water writer said he had a role in mind for him, but it wasn't ready yet.

"Nine years later, from our first meeting at Sundance, Taylor had something for me, and it was Landman," he recalled. "I signed onto this project with no script — nothing but the idea of what it was going to be — and Billy Bob Thornton. And I said, 'Sure I'm in! Yes, sir, I'll do that.'... That man is a national treasure of — what nation, I do not know!"

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Hamm appeared at The Elvis Suite presented by Darling&Co. at Sundance to promote his latest project: The Big Fix: A Jack Bergin Mystery, an eight-part Audible audio drama about corruption in 1950s Los Angeles that debuts April 24.

"I'm tremendously grateful, tremendously humble about anything I've achieved in my career," the Mad Men and Fargo star said. "I'm also very proud of the work I've put into it. I don't want to act like I stumbled into this.... There's no false modesty. I've worked really hard to get here. But, there's also the opportunity of coming to places like [Sundance], to have the opportunity to be able to give back — to pay it forward, that's the stuff."

"When you get enough people in one place, bumping into each other and talking to each other, good things happen," Hamm said. "That's why I mention Tyler. Good things happen when creative people bump into each other."

Nominated for 14 Primetime Emmy awards, Hamm won Outstanding Lead Actor in a Drama Series in 2015 for his role as troubled ad man Don Draper in Mad Men.

He next stars in Apple TV+ original drama Your Friends & Neighbors, premiering April 11, as a disgraced hedge fund manager who resorts to stealing from his affluent neighbors’ homes, but discovers that knowing their secrets might be more dangerous than robbing them.