New Jersey Transit suspended rail service into and out of New York City on Friday night after members of the locomotive engineers’ union called out sick en masse to protest a lack of holiday pay on Juneteenth.

Nearly 80 New Jersey transit trains were canceled in what officials called an “illegal job action” — sending commuters scrambling for a way to get their destinations from Penn Station as Father’s Day weekend kicked off.

Union members were negotiating a new collective bargaining agreement that includes Friday’s observance of Juneteenth as a holiday, NJ transit said.

“With today’s engineer call outs at nearly triple the rate of an average weekday, it is clear that this is the result of an illegal job action,” the agency said in a statement.

“NJ Transit is disappointed that the union would perpetrate such an act on the more than 100,000 commuters who depend on NJ Transit rail service every day,” the agency said in a statement.

“We intend to explore all legal remedies in response to this illegal and irresponsible action.”

The Brotherhood of Locomotive Engineers and Trainmen did not immediately return a request for comment from The Post.

The rush-hour announcement canceled dozens of trains on the Northeast Corridor and North Jersey Coast lines, NJ Transit said.

The last train out of Manhattan was scheduled to depart at 8:05 p.m., according to the agency’s abridged schedule. Some trains were scheduled to continue to run from upstate Rockland and Orange Counties to Hoboken in the later evening hours.

New Jersey Transit is the third-largest regional transit system in the country.

Train tickets were being cross-honored on NJ Transit buses, officials said.

Juneteenth was signed into law as a federal holiday last year. The June 19 holiday commemorates the day in 1865 that Union troops began enforcing the Emancipation Proclamation of 1862 in Galveston, Texas.

With Post wires