A passenger described the “dystopian” scene on the world’s largest cruise ship after a man went overboard Sunday and died — including the premature celebration that broke out when passengers heard he was pulled from the water.

Zachary Normandin, 31, told The Post that some 300 passengers eating dinner on Royal Caribbean’s new Icon of the Seas cheered when the captain informed the ship that the missing traveler was found.

“Everyone in the dining room clapped and we’re like ‘yeah,’” the Connecticut resident said. “We assumed that the guy was fine.”

But it emerged that the passenger — who has not been identified — was dead, and the 1,200-foot cruise ship continued on its voyage.

Normandin said he heard from several other passengers that the man jumped from the ship, though the Coast Guard only said he fell overboard.

The result was an almost surreal atmosphere as most travelers continued to party as if nothing had happened.

“I don’t think everyone knows about the guy dying. I think it’s kind of purposely silenced,” Normandin said, adding he doesn’t think Royal Caribbean wants to scare anyone.

The Icon of the Seas, which can carry up to 7,000 passengers and 2,000 crew members, was on the first day of a seven-day voyage around the Gulf of Mexico when the tragedy occurred. It’s not due back in Miami until June 1.

It has made two ports of call, including in Honduras and Costa Maya, Mexico.

The Coast Guard told The Post Monday night the cruise ship deployed rescue boats, located the man and brought him back on board.

“He was pronounced deceased,” the Coast Guard said.

Normandin, a married father of one, said the Icon of the Seas’ captain initially revealed a man had gone over the side of the ship and the vessel was forced to turn around in hopes of finding the missing traveler.

“I thought we were going straight back to Miami, I thought that was it. But no, everything just kept on going,” said Normandin, who posted part of the rescue mission on social media over the weekend.

Normandin said he’s surprised how many passengers went about their business during the search and in the aftermath even as news spread that the passenger had died.

“I think people were just trying not to think about it, maybe, I don’t know,” he said.

“It just seemed like more people would have been like ‘Oh my gosh, what’s going on,’ but no, people were just going about their day. It’s just kind of dystopian.”

Week-long voyages on the mega-ship generally cost around $1,500 to $2,000.

Royal Caribbean hasn’t said much about the incident, citing the need to give the grieving family privacy.

“Prayers to the family, I just hope they get through this,” Normandin said. “I just wish I knew who they were so I could reach out to them and hug them or something.”