Lady Gaga’s father is refusing to pay rent on his Grand Central Terminal restaurant and bar, claiming the train hub’s homeless population is killing his business.

Joe Germanotta claims homeless people in Grand Central’s basement food court cut his business by 30 percent since he opened Art Bird & Whiskey Bar in 2018.

“The homeless go in there to stay warm. We’re compassionate, but it affects our customers,” Germanotta told The Post this week. “When the homeless invade our areas, it becomes a less attractive place.”

Frustrated with what he perceives as the MTA’s refusal to address the issue — along with a bevy of other ongoing issues, like a rodent problem, poorly maintained restrooms and outdated seating — Germanotta is refusing to pay a portion of the $40,000 rent and $10,000 in fees he owes each month.

The MTA is seeking $260,000 in rent and fees, which he says he must pay in the next two weeks or the authority will begin the eviction process.

“I don’t think they were prepared [to manage the space],” he said. “Quite frankly, I think they’re more interested in running the trains.”

“I’ve seen people washing their hair in the sink. I’ve seen a turd in the urinal,” he said.

If steps aren’t taken to “upgrade” the space, Germanotta said, he’ll leave — and expects to be compensated for the money he’s invested.

Other food court vendors said the homeless are hurting their business, too.

“This is a tourist attraction. Right now it looks like a homeless attraction. It’s not even a tourist attraction,” said Tamarsha Sandiford, 38, manager at Wok Chi. “Sometimes my customers buy stuff and they can’t even sit and eat because they all take over all the seats.”

Sandiford and others said routine visits by outreach workers failed to address the issue, and that more must be done.

“It’s bad for business. They’ll be approaching [customers] asking for food or money,” said Tri Tip Grill manager Jimmy Ponce, 31. “They yell at customers because they wouldn’t buy them what they wanted.”

“We entered into the lease and expected certain conditions for our business,” he said. “They have to update it to conditions that are suitable for a food court.”

Germanotta’s dispute with the MTA was first reported by The Wall Street Journal.

MTA officials previously blamed a 3 percent drop in food court sales in 2018 on “outdated furniture design” and the “continuing challenge of the homeless population,” but the agency claims sales increased by 6 percent in 2019.

MTA rep Tim Minton called the food court “a great place to do business,” and said Germanotta had negotiated but refused to sign an agreement to defer his rent payments.

“This is a landlord-tenant dispute, pure and simple, in which the tenant seeks to blame his financial struggles on anyone but himself,” Minton said. “The fact that Mr. Germanotta does not appreciate someone who is less fortunate having a cup of coffee near his business is not the problem of the people of the state of New York, who don’t expect to have to subsidize his struggling business.”