Families of 9/11 victims are outraged that a climactic scene involving a greedy hedge-funder in the season finale of Showtime’s “Billions” was filmed at the Ground Zero Memorial.

The May 7 episode shows Bobby “Axe” Axelrod, played by Damian Lewis, in a tense conversation with his confidante Wendy Rhoades (Maggie Siff) next to the twin reflecting pools in the footprint of the destroyed World Trade Center. A fleet of FBI agents then swoops into the memorial plaza and arrests him on insider-trading charges.

The scene has reignited the debate over whether the site should be off-limits to commercial or entertainment interests. Some families say the sacred burial ground should not be cheapened as a Hollywood backdrop. Others believe the site is a part of the fabric of the city and a symbol of its recovery — and that media access helps ensure its history is never forgotten.

The nearly 4-minute scene was a “disgusting disgrace,” fumed one 9/11 family member.

“It’s outrageous. The 9/11 Memorial and Museum people are out exploiting the dead when [the grounds] should be a place of respect and sanctity,” Sally Regenhard told The Post through tears.

She lost her 28-year-old son Christian, an FDNY probie, in the attacks. His body has never been recovered.

Regenhard plans to file a protest with Showtime executives to voice her displeasure.

Some 8,000 unidentified body parts — the remains of 1,100 unidentified people — are stored in an out-of-sight “remains repository” at the museum’s underground home. Many victims’ loved ones, including Regenhard, are against interring the remains there and want the National Parks Service to take control of the site.

“His memory is being defiled,” Regenhard said. “I’m sickened that they are shooting television shows over the graves of the people who died for this country.”

Sept. 11 families advocate Glenn Corbett, a fire-science professor at John Jay College, said, “This is a graveyard, not a movie set.”

Paul Sipos, 76, who lives seven blocks from Ground Zero, said he was “revulsed” by the scene and will no longer watch the show, which follows the trajectory of a ruthless but at times compassionate Wall Street exec whose wife perished on 9/11.

“I was outraged that they [memorial administrators] would do something like that,” Sipos said. “It was shocking.”

Sipos was galled that the credits acknowledged the museum’s assistance in filming and is suspicious of the museum’s motives for letting Hollywood take over Ground Zero for the two-day shoot in early December.

“I thought, ‘Well somebody must be making money off this,’ ” he said. “They need money to keep that thing afloat. It’s expensive and there are a lot of salaries to pay.”

A spokesman and a board member of the memorial — which in its first full year of operation ended in the red, with costs outstripping revenues by $25.2 million — refused to answer questions about whether the program paid the institution or if the public was denied access during the shoot. Showtime did not respond to messages.

“Billions” showrunners did have to obtain a license from both the city and the 9/11 Memorial nonprofit. The memorial charges a $150 application fee, but “additional location and usage fees may apply,” according to its online guidelines.

The city said it issued its permit only after museum officials “sanctioned the shot.”

Regenhard said she was baffled by the memorial’s policies and pointed to the ugly 2016 incident where memorial security guards stopped a group of North Carolina elementary students from singing the national anthem at the site because they didn’t have a permit.

“How hypocritical that they would stop patriotic and respectful schoolchildren but would permit a commercial endeavor about horrible, greedy people,” she said, adding the “New York City agency that allowed this to happen” should be condemned.

City Hall spokesman Ben Sarle defended the move.

“The head of the Memorial told us he has received many calls from families who feel that the scene in ‘Billions’ brought attention to the Memorial in a respectful and fitting way,” he said.

And not all 9/11 families were upset. Debra Burlingame, sister of Flight 77 pilot Charles Burlingame III and a member of the memorial’s board, said the “Billions” scene had a “solemn” feel and was “done beautifully.”

“This is just another way of remembering — it makes it part of our daily lives,” she said.