Hugh Dancy flew around the rink, gliding from one foot to the next atop the black matting. The wind tousled his hair, the pattern on his houndstooth blazer blurring as he picked up speed.

“It’s stopping that’s the issue,” Mr. Dancy said, with typical self-deprecation, as he passed.

A star of the revived “Law & Order,” in which he plays a diligent assistant district attorney, and of the latest “Downton Abbey” film, Mr. Dancy, 46, had come to the Rink at Rockefeller Center to pursue a pastime that predates his love of acting: roller-skating.

At his boarding school, the Dragon School in Oxford, England, boys spent half the year playing tennis and the other half roller-skating across the tennis courts. “There were a couple of kids who were extremely good at it,” Mr. Dancy said. “And then, the rest of us.”

He mostly remembers lying in a row while a daredevil classmate — “the Evel Knievel of my 10-year-old peer group,” Mr. Dancy recalled — jumped over them.

Mr. Dancy — charming, self-possessed, self-effacing — has rarely skated since. But on a recent sun-drenched Tuesday morning he decided to try again, mostly to see if he ought to take his sons, 9 and 3, on a future trip. (They live in the West Village neighborhood of Manhattan, along with Mr. Dancy’s wife, the actress Claire Danes.)

He arrived at the rink just before 10 a.m., paid the $20 admission fee (plus $10 for skate rental) and affixed to his blazer an entry sticker that doubled as a liability waiver. In the locker room, he traded his Adidas sneakers for a handsome pair of the rink’s blue suede skates, pulling the red laces tight. He stood up from the bench and took a few exploratory steps.

“This is not all coming flooding back,” he said, tottering slightly. Tottering a little more, he made his way toward the rink. “What an embarrassing procession,” he added.

An employee of the rink, Demis Maryannakis, gave him a few pointers as he passed. “Arms out,” he called. “Knees bent!”

Mr. Dancy began to skate, gradually lengthening his strides as he picked up speed. Mr. Maryannakis looked on approvingly, shouting, “You’re awesome!”

Was everyone always this nice to him? “They know I’m about to injure myself,” Mr. Dancy said.

Tourists watched him whiz around the rink, one of about eight skaters. Some took cellphone photos of him, though several struggled to place him. “He is ridiculously handsome,” one woman wondered aloud. “Is he from ‘Glee’?” Another guessed the procedural “NCIS.” Wrong again.

Mr. Maryannakis did not fare better. “Totally forget his name,” he said.

That no one could identify Mr. Dancy is perhaps a tribute to his emotional shape-shifting and his somewhat eclectic career. With his floppy hair and posh accent, he seemed destined for period pieces and the occasional rom-com. He made those.

Looking up from the rink at 30 Rockefeller Plaza, he remembered shooting a kissing scene from the 2009 comedy “Confessions of a Shopaholic” on one of its terraces. But he has also acted in plenty of contemporary dramas and even the occasional action movie, including “Black Hawk Down,” usually with an American accent.

“I’ve been able to work in my own accent here, but only onstage,” he said.

From 2013 to 2015, he starred as an F.B.I. profiler on the NBC crime series “Hannibal.” That show — gorgeous, lurid and violent — made his current job, on the orderly procedural “Law & Order,” feel comforting by contrast. His turn as a filmmaker in the latest “Downton Abbey” movie felt restful, too.

“I had played increasingly dark characters,” Mr. Dancy said. “So I was actually quite happy to play somebody who is basically not.”

That morning, the rink’s pink lights turned his complexion rosy. He began to try out some fancy footwork, crossing a leg behind the other as he skated past the gold Prometheus statue, which glittered in the sun. The edge of the rink delivered electric shocks when touched, an inducement to keep skating. Blondie played over the speakers, then Prince.

“Prime skating music,” Mr. Dancy remarked.

Dispassionately, he assessed his abilities: “I’m a moderately coordinated 46-year-old,” he said. “The coordination I’ve always just assumed was somewhat innate turns out to be a little shakier than I had planned on.”

Would he attempt a spin? “Not deliberately,” he said, wiping his brow. “This is exhausting.”

Another rink employee had a more forgiving analysis. “He has a perfect mind-set,” Daniel Carr said as he watched Mr. Dancy skate. “And he has great balance, great crossover. He bends his knees, he’s focused.”

Mr. Carr then offered the ultimate compliment. “You’re a very fashionable skater,” he said to Mr. Dancy. “When you look good, you feel good.”

Mr. Dancy felt good. So good that he decided to return to the rink later in the spring with his two boys. He asked Mr. Carr if the rink offered lessons and was pleased to learn that it did. “I feel this is a dress rehearsal,” Mr. Dancy said.

Even as he said it, someone else’s child caromed past him, skating at twice Mr. Dancy’s pace. He smiled ruefully, perhaps recalling his daredevil classmate. “My general experience in these things is being shown up by children,” he said.