Chris Christie’s big mouth has gotten him in trouble again — this time on an Amtrak train, where he was booted from a quiet car Sunday for yapping loudly at his staff.

The New Jersey governor, a Republican presidential candidate, was sucking down a strawberry smoothie on the 9:55 a.m. New York-bound Acela train when he went off the rails, making loud comments to his security officers.

“On a very full train this morning, the governor accidentally took a seat in Amtrak’s notorious quiet car,” his spokeswoman, Samantha Smith, explained to The Post.

“After breaking the cardinal rule of the quiet car, the governor promptly left once he realized the serious nature of his mistake and enjoyed the rest of his time on the train from the cafe car.”

Christie was reportedly talking to his state-trooper guard about a seat mix-up and making phone calls on the train, which had departed from Washington, DC.

“After about 10 minutes, the conductor asked him to stop or go to another car. He got up and walked out again yelling at his [security guards],” rider Alexander Mann told Gawker. “He was drinking a McDonald’s strawberry smoothie.”

But Katie Klabusich, a woman who said she was sitting near Christie in the quiet car, tweeted that the governor was “super courteous” after being told to move and was “possibly the least intrusive in-public phone person ever.”

“When the conductor came by to check tickets, he just said, ‘sir, this is the quiet car.’ CC [Christie] had the same reaction as anyone,” she recounted on Twitter.

Klabusich, tweeting as @Katie_Speak, added that Christie replied, “You’re kidding. It’s the quiet car? Alright.”

He then told the person on the phone, “I gotta go, I’m in the quiet car. Call you back,” she recalled.

“Did he appear annoyed? Sure. Apparently having a s- -t logistics day & someone f- -ked up. Was he screaming, causing a scene? Hardly,” Klabusich tweeted.

Others blasted Christie as tone deaf.

“Not even the quiet car is safe from Chris Christie’s big mouth,” Republican consultant Jessica Proud told The Post.

Susan Del Percio, a Republican political consultant, said, “Unfortunately, it plays into his narrative of being loud and outspoken, although with his standing in the polls, it likely won’t make much difference.”

People also took to Twitter to hound Christie, with at least one user landing a gut punch about him undergoing gastric-band surgery in 2013 to lose weight.

“If only there was a #lapband for obnoxious,” @CitizenSnap wrote.