The editor of a left-leaning British newspaper offered its staffers counseling to cope with Donald Trump’s “upsetting” victory in Tuesday’s presidential election, The Post has learned.

Katherine Viner, editor-in-chief of The Guardian, urged journalists at the newspaper’s UK and Australia offices to contact their colleagues in the United States to “offer your support,” according to a copy of her email obtained by The Post.

“I know the result has been very upsetting for many colleagues,” she wrote.

“If you want to talk about it, your manager and members of the leadership team are all available, as is the People team.”

Viner added that employees upset by Trump’s return to the White House can access free mental health support from internal company portals, according to the memo.

“The election has exposed alarming fault lines on many fronts, which we will be examining in the weeks and months ahead,” Viner wrote.

One source trashed the Israel-bashing newspaper’s offer of counseling as “dumb s—.”

Another mocked any triggered journalist, saying sarcastically: “It’s all so difficult!”

A Guardian spokesperson told The Post: “We regularly remind colleagues about our employee assistance program — a function that any responsible international media organization has available for staff at all times.”

The newspaper’s front page on Thursday showed an image of a smiling Trump with the headline: “American dread.”

Viner — who has been in charge of 203-year-old London publication since 2015 — also attempted to fund-raise off of Trump’s political comeback, which she called “an extraordinary, devastating moment in the history” of the US.

She penned an essay Wednesday urging readers to donate in order to help it “stand up to four more years of (Trump).”

“We will stand up to these threats, but it will take brave, well-funded independent journalism… that can’t be leaned upon by a billionaire owner terrified of retribution from a bully in the White House,” Viner wrote, alluding to Washington Post owner Jeff Bezos.

Bezos, the Amazon founder, blocked his editorial board from endorsing Harris, sparking resignations from a few of his journalists as well as anger from readers.

The billionaire mogul denied that the move was done in order to curry favor with Trump so as to benefit his business interests.

The Guardian is owned by a trust whose purpose is to ensure financial and editorial independence in perpetuity. Since most of the online content is free, the business model is built around voluntary contributions from readers.

While the newspaper’s main offices are in London, it has expanded its US footprint, where it employs about 200 workers.

Recent financial disclosure forms indicate that it employs 2,500 staffers worldwide, with most them concentrated in the UK, US and Australia.

Viner’s outreach to staff follows a move this week by an elite $65,000-a-year private school in New York City that said it would allow “emotionally distressed” students to skip class on Wednesday — a decision that was blasted by parents, including comedian Jerry Seinfeld, whose kids once attended the institution.

The Ethical Culture Fieldston School sent a note to parents saying that the election “may be a high-stakes and emotional time” for students, who were not assigned homework on Election Day.

Kids will also be allowed “excused absences” on Wednesday or whenever the election results are announced if they feel unable to “fully engage in classes,” according to the note, which was first reported by The New York Times.