King Charles III and Queen Camilla met Wednesday with dozens of families who lost loved ones in the 9/11 terrorist attacks — hugging the relatives in a tender moment that showed off their “down to earth” sides to regular New Yorkers.

The British monarch and his wife, during their visit to the 9/11 Memorial and Museum, asked the grieving family members to recall their favorite memories of their slain kin as they made their way down a packed procession line.

“Anyone who thinks that the King and the Queen are not down to earth — nothing is further from the truth,” said Anthoula Katsimatides, whose brother, John, was working as a broker in the North Tower on Sept. 11, 2001.

“I showed them my picture of John and Camilla said, ‘Oh, he’s quite a looker!” she recalled to The Post after.

Katsimatides was surprised at the “warm” and “down to earth” nature of the royal couple — which she said made the receiving line so comfortable, that she felt emboldened to ask Camilla for a hug and to tell the king: “You are so cute!”

The royal couple eagerly listened as the lifelong Queens resident told them about her late brother’s beautiful smile, quirky personality and love for his Harley-Davidson motorcycle.

“They’re so cool,” she said of the septugenarian pair.

The trio even bonded over the surreal experience of seeing the memorial’s rushing water falling into the reflective pools at Ground Zero.

“The sound of the water is just so soothing and it’s so indicative of the pulsing and the movement of life that. I thought it was really interesting that they liked that the most,” said Katsimatides, who has served on the 9/11 museum’s board for nearly a decade.

“[Camilla] said, ‘Are you happy with this place?’ I said, ‘This is the most important place to me because when I’m long gone, this is the official repository of John’s memory,'” she said.

“For people who lived through that day and lost their loved one in such a horrific way — John was never recovered — people don’t understand how important this memorial is to us,” Katsimatides continued.

“This is where John took his final breath. To me, this is everything.”

James and Patrick Dowdell were also pleasantly surprised at how “personal” the moment was, with the brothers expecting the royals to offer a handshake and breeze on to the next family on line.

The royals asked the pair about their father, Lt. Kevin Dowdell, who was one of the eight members of FDNY Rescue Company 4 killed in the attacks.

“We really appreciated him stopping by,” said James, who followed in his father’s footsteps in the wake of his death and was recently promoted to lieutenant — the same rank his hero dad held at the time of his death.

“He was a great man who lived a life of service and died with his whole company down here,” he said.

James was wearing his uniform for the occasion, which earned him a compliment from the king: “Very sharp!”

The opportunity to tell the monarch about their father was a “humbling experience,” said Patrick, who followed his dad’s legacy by graduating from West Point and enlisting in the military.

The brothers are eager to tell their father’s story as the years wear on, especially to those who are too young to recall the attacks that killed 2,977 victims.

“There’s just a huge amount of people that don’t have a personal connection to it, so we try to make a personal connection: ‘here’s who we are, here’s a little bit about our family and our dad and what he did.’ It makes it a little bit more personal to people, and they can connect to it a little bit easier,” said Patrick.

“It doesn’t seem like it was that long ago because it’s just always there. But, we have kids now, and they’re learning. They know who grandpa Kevin was and what he did. And it’s part of who they’re going to be as well.”