One of the largest municipal unions, representing security guards at Big Apple public schools, colleges, housing complexes and homeless shelters, has endorsed former Gov. Andrew Cuomo for mayor.

The head of the 25,000-member Teamsters Local 237 insisted that Cuomo, 67, is best positioned to “address the problems we’re facing.”

“Cuomo knows how to operate things. He knows how to run the city,” union president Gregory Floyd told The Post Thursday of the pol staging a comeback bid.

“He’s the best candidate in the race to address the problems we’re facing.”

Floyd said he’s known Mayor Eric Adams for 30 years and didn’t back him for mayor in 2021.

“Am I surprised?,” he said sarcastically of Adams’ scandal-scarred tenure at City Hall.

As for New York City Council Speaker Adrienne Adams — who announced her mayoral run Wednesday — Floyd said she was “very late in entering the race.”

The Teamsters’ endorsement of Cuomo is “important” because it “breaks up support within the municipal unions,” a labor insider said.

This means that neither Eric Adams nor Adrienne Adams (no relation) can count on overwhelming support from the unions representing the hundreds of thousands of city government employees.

Cuomo also recently landed an endorsement from some of the construction trade unions, including the New York City District Council of Carpenters.

Mayoral primary elections are scheduled for June 24.

The former three-term governor is making a comeback bid for mayor after resigning as the state’s chief executive following a slew of sexual misconduct accusations, which he denies.

Cuomo’s strengths outweigh his flaws, Floyd said, noting that President Trump was elected president despite his 34-count conviction for falsifying business records in the hush money case involving porn star Stormy Daniels.

Trump claimed the prosecution was a partisan witch hunt.

“We need someone who can run the city correctly,” Floyd said.

Cuomo is the front-runner in the Democratic primary for mayor, according to recent polls.

Other candidates running in the Democratic primary include state Sens. Jessica Ramos and Zellnor Myrie, city Comptroller Brad Lander, state Assembly Member Zohran Mamdani, ex-Assemblyman Michael Blake, former city Comptroller Scott Stringer and financier Whitney Tilson.

Guardian Angels founder Curtis Sliwa is the declared Republican candidate for mayor.

Cuomo landed another key endorsement Thursday, with former Bronx Borough President Ruben Diaz Jr. announcing he was backing the ex-gov.

Diaz had been a close ally and backer of Eric Adams, but also worked closely with Cuomo when the latter was governor.

“New York City is at a pivotal moment, one that requires a steady hand and strong leadership to deal with the issues we face at home in our streets and the federal government’s dramatic turn away from our values,” Diaz said.

In making his endorsement, Diaz cited Cuomo’s record of helping The Bronx, specifically tearing down the Sheridan Expressway and returning access to the waterfront to residents, improving the Hunts Point Market and approving the construction of four new Metro North stations.

“I am proud to support Governor Cuomo to be our next mayor, and I know he will be the fighter we need to deliver effective solutions on crime, disorder, housing, affordability, education and so many other issues,” he said.

Meanwhile, during a press briefing following his Teamsters endorsement, Cuomo was asked about his regrets and what would he have done differently as governor if he could go back in time.

“I would have added more police to the MTA if I knew New York City was going to be cutting police, right?,” he said

He said the state was unprepared for a once-in-a-century pandemic.

“But if you knew you were going to face a pandemic, I would have done much more preparatory work in the years preceding the pandemic. You know, we didn’t have supplies of N95 masks …. . There were supposed to be regional stockpiles of this equipment, but it turned out held by the federal government. But it turned out when they went through the federal stockpiles, basically, the cupboard was bare. So I would have done that on the state side,” said Cuomo