A French man allegedly sexually abused a sleeping woman he sat next to in the first-class cabin of a Miami-bound flight — and returned to leave her a creepy note, according to court records.

Guillaume Sebastien Roger Mattler, 48, faces a count of abusive sexual contact for the disturbing incident that unfolded Tuesday on Swiss International Air Lines Flight LX64, according to a federal criminal complaint obtained by The Post.

Mattler and a 29-year-old woman, whom he did not know, were “seated next to each other in the first class cabin” on their way to the Sunshine State from Zurich, the complaint said.

The woman dozed off during the international flight when two other passengers witnessed the stomach-turning behavior.

The two passengers allegedly spotted the French national touching the woman as she slept, with one alarmed man whipping out his cellphone to take several videos and alerting his friend, according to the document first reported by Local10.

After the passenger became “very concerned,” he alerted a flight attendant, the complaint alleged.

“Witness 2 observed Mattler moving his hand in a ‘submarine’ motion, as if trying to get his hand under the Victim’s clothing and/or between her legs,“ an FBI Special Agent wrote in the complaint.

As the flight attendant rushed to assess the situation, they allegedly witnessed Mattler with his hand on the stranger’s “crotch, over her jeans, making a scooping or rubbing motion on her vagina.”

After the abuse occurred, Mattler was unable to tell the flight attendant whether he knew the woman and was moved to coach, federal officials alleged.

When the flight attendant woke the woman to tell her what had happened, she was “shocked” and “began shaking and crying,” court documents stated.

After Mattler was returned to his seat to fetch his belongings, the creep allegedly tried to hand the victim a note that said “you look beautiful when you are sleeping,” the complaint added.

He then allegedly claimed to investigators that “nothing happened on the flight.” But, when confronted with video evidence, the creep admitted that he “touched the woman sitting next to him and that he did not think it was such a big deal,” court documents said.

After claiming to have touched only her lower back and upper buttocks, the frisky Frenchman disturbingly said, “he touched whatever he could reach from across the armrest,” investigators claimed.

“Mattler advised his initial intention was to get the woman’s phone number and give her his,” an FBI agent wrote. “He then provided the note from his pocket that was written on his business card that read ‘you look cute when you sleep,’ along with the flight information and his seat number.”

He also allegedly informed agents that he had taken photographs with his phone but deleted them before officers could find them.

Mattler appeared in Miami federal court on Wednesday and will return to court on Monday, Local10 reported.

Prosecutors wish to keep him behind bars for being a flight risk and a danger to the community, the outlet reported.

Court documents stated he also initially declined assistance from the French consulate.