The Met will soon take over the Whitney Museum of American Art’s Marcel Breuer building as additional exhibition space and plans to redesign the wing for Modern and contemporary art, a space long considered inadequate and ill conceived. Mr. Campbell said the museum recently completed a five-year strategic plan focusing on its collection, scholarship, audience development and “institutional excellence.”

“So Dan is coming in at a very exciting moment,” he added.

Like his recent predecessors, Mr. Weiss, who begins the job this summer, will report to the Met’s director. But Mr. Campbell said that the fund-raising duties of the presidency — Ms. Rafferty’s forte — would be spread out; the museum is searching for a senior vice president for advancement who would take on the chief burden of fund-raising, to “free Dan up to an extent” to focus more on the museum’s internal functioning and how it positions itself in New York and internationally.

“What the selection committee saw in him was an individual who was deeply thoughtful and very effective in evolving institutions he’s worked with in very positive ways,” said Mr. Campbell, who added that he was “looking for a thought partner.”

Mr. Weiss, who was born in Newark and raised on Long Island, began his career in museums at a fairly humble level: as a museum shops manager at the John F. Kennedy Center for the Performing Arts in Washington. Before earning his doctorate, he earned an M.B.A. from the Yale School of Management in 1985 and worked for the consulting firm Booz Allen Hamilton in New York. From 2005-13 he was president of Lafayette College in Easton, Pa., where he increased the size of the permanent faculty by more than 10 percent. Among his scholarly publications is the 1998 book “Art and Crusade in the Age of Saint Louis,” which examines the art patronage of Louis IX.

Mr. Weiss said he viewed the Met — which has emerged from some rocky years during the recession and is now on a solid footing with its endowment — as an institution whose main challenge was to attract an even broader and more diverse audience. It needs “to be welcoming to everyone who has an interest in art,” he said, “not just scholars.”

Of the museum’s financial ability to do that and to take on huge projects like the Breuer building and the wing redesign, he added: “The resources are vast, but so are the expenses. Nothing is broken, nothing is wrong, but there’s always the opportunity to do better.”