City University is paying liberal economist and columnist Paul Krugman $225,000 to become a professor — but he doesn’t have to teach a course next year.

The rich deal for Krugman — a Nobel laureate who rails against income inequality — was spelled out in documents obtained by Gawker.

Krugman will serve as a “distinguished scholar” in the CUNY Graduate Center’s Luxembourg Income Study Center.

“As a distinguished professor in the Ph.D. program in economics, your nine-month salary will be $225,000. During year one (2015-2016), you will not be expected to teach or supervise students,” said a letter to Krugman, explaining how much he would get and what he would have to do for his paychecks.

“Instead, you will be asked to contribute to our build-up of LIS and the inequality initiative and to play a modest role in our public events.”

In year two and thereafter, Krugman, a New York Times columnist, is expected to teach one seminar per year, the letter said.

Krugman described the offer as “remarkably generous” in his response to CUNY.

He will be provided with a graduate assistant, an annual research/travel fund of $10,000 and up to $10,000 in moving expenses, according to the documents.

CUNY did not spell out Krugman’s compensation when it announced in a February press release that he will be leaving Princeton University to come here next year.

Gawker obtained the details through a Freedom of Information Law request.

CUNY previously caught flak when it offered to pay four-star general and former CIA Director David Petraeus $150,000 to teach a class.

The deal was subsequently squelched, and Petraeus agreed to take only $1.