In Mr. Cohn, Mr. Trump is not only turning to yet another Goldman hand — and a registered Democrat — but he is also choosing a financier whose thinking about the economy has stood in contrast to the president-elect’s more nationalistic views.

At a conference in Florida soon after the election, Mr. Cohn said the big problem facing the country and the world was a “global growth issue.”

“We’re trying to solve it with domestic policy,” he said. “It’s not going to work.”

While Mr. Trump has criticized companies that have moved their work force overseas, Mr. Cohn has been candid about Goldman’s international outlook: “We have a globalized work force, so when I need to go out and hire the incremental worker, I go out and look around the world and see where that incremental worker is available.”

Mr. Cohn, though, has agreed with Mr. Trump about the need to lighten the regulations that have been imposed on banks like Goldman since the financial crisis.

In another interview at the conference, with CNBC, Mr. Cohn said he was “cautiously optimistic” about a Trump administration.

“We’re all giving President-elect Trump and his transition team the benefit of the doubt,” Mr. Cohn said. “We’re all waiting to see what happens.”