At Mustang Harry’s, it’s all in the family.

The longtime Midtown sports bar is celebrating its 30th anniversary — and owners Ian and Niall Conroy attribute the beloved watering hole’s longevity to their efforts to form a tight community of regulars.

“We run it like a family-run restaurant: our patrons have been friends over the years, and the ones that come in for lunch come in every week, multiple times a week,” Ian, 63, told The Post ahead of the bar’s anniversary celebration kickoff on Thursday.

Opened in 1995, Mustang Harry’s was inspired by the brothers’ own family’s pub in County Tipperary in Ireland — and the duo’s own children have all held various positions on staff.

“We treat everyone like they’re family,” he said. “It’s as simple as that.”

The brothers will be holding a slew of celebrations over the weekend to honor its lasting status on Seventh Avenue, starting with a New York Rangers watch party, live music and giveaways — plus 1995 menu prices Friday and Saturday.

Cocktails like White Russians and Greyhounds will run for $9, while brews like the “Harry’s Lager” will start at 95 cents, the duo said.

“It’s a way of giving back to people. and making people feel [like it’s a] home away from home – coming in here to relax. You start by putting a smile on their face,” Niall, 60, told The Post.

“We have a lot of staff members [that have worked] here for more than 20 years,” Ian added, “and they treat the customers the same way we treat them.”

The Conroy brothers recounted how, over the years, the bar has gone through city tragedies like the Sept. 11 attacks and Hurricane Sandy in 2012.

“9/11 was probably the first huge issue that we went through,” Ian said. “9/11 changed things for everybody, [business] was slow, but then gradually we all got through it and we weathered that storm because the city came together.”

The tavern served as a safe haven for neighbors during Hurricane Sandy to charge phones, use restrooms or simply sit down free of charge, the brothers recalled.

“We were one of the few places that weren’t affected by the loss of power,” Ian said, “so we put a sign outside the door and just invited anybody who needed to come in … that’s Irish hospitality.” 

The pandemic served as the latest challenge for the business owners – and one that hasn’t fully stopped affecting them.

“Lunch still hasn’t gotten to where it was,” Ian lamented, adding that Mustang Harry’s sister location, Mustang Sally’s, was a victim of the pandemic. “People are still working from home– but the trajectory is still moving in the right direction.”

The brothers are still working on building up their lunch crowd as more Midtown workers return to office buildings five years later, Ian said. In the meantime, they are sustained by dozens of weekday regulars for lunch and hundreds that flock to the tavern for evening hockey and basketball games.

“A big part of [our success] is Madison Square Garden — MSG has no idea how many businesses they help in the area, we’re one of them,” Ian said, noting earlier this year that the New York Knicks’ success helped to give Mustang Harry’s a much-needed boost.

Of all the Midtown watering holes, the Conroys affirm theirs is a favorite among basketball, football and hockey fans alike.

“I think you retain the Irishness,” Niall said of what makes the bar unique. “It’s an American bar, but with Irish hospitality.”