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.