Before joining N.Y.U. in 1999, she was a professor at U.C.L.A.
The selection of Dr. Mills, 65, was announced Wednesday morning in a news release, which said she was chosen from among 100 candidates for the post.
“I love N.Y.U.,” Dr. Mills was quoted as saying in the release. “I am filled with enthusiasm, emotion, and, most of all, gratitude.” She said she wanted to step into the role with “fresh eyes,” but did not lay out any specific plans for changes at the university.
She was scheduled to meet separately on Wednesday with groups of students, faculty and administrators.
Dr. Hamilton, who is remaining at N.Y.U. as a professor, was credited with slowing the growth of the university’s tuition charges, and with increasing financial aid packages for students. Even so, attending N.Y.U. remains a financial struggle for many students.
Evan Chesler, a Manhattan lawyer who served on the presidential search committee, said Dr. Mills was chosen partly because the committee believed she could be a prolific fund-raiser, though that has not previously been one of her responsibilities.
“We’re very tuition-dependent, at a time when many, many American families can’t afford tuition for students,” said Mr. Chesler, a partner at Cravath, Swaine & Moore. He said that the university’s endowment, relative to the number of students it enrolls, is “a fraction of what our peer schools have.”
The university’s total published costs for each undergraduate add up to nearly $90,000 a year, including tuition, housing, food and other expenses. About half of its students receive some type of financial aid toward those costs.
Among the challenges Dr. Mills must navigate as president will be the sometimes fraught relationship between its ever-expanding Manhattan campus and its neighbors in New York, as well as the geopolitical tensions and other issues affecting its operations in Abu Dhabi, Tel Aviv and Shanghai.