•Elizabeth Magill, president of the University of Pennsylvania, refused to say whether students who called for the genocide of Jews would be punished.
•Ms Magill has previously apologised for her testimony.
A US university president has quit after her comments about antisemitism on campus during a Congressional hearing triggered a major backlash.
Elizabeth Magill, president of the University of Pennsylvania, refused to say whether students who called for the genocide of Jews would be punished.
The university said she "voluntarily tendered her resignation" but will stay in post until a replacement is found.
Ms Magill has previously apologised for her testimony.
She made the controversial comments while appearing in front of a House of Representatives committee on 5 December alongside the presidents of Harvard and MIT, Claudine Gay and Sally Kornbluth.
They were asked by Republican New York Congresswoman Elise Stefanik: "Does calling for the genocide of Jews violate [your university's] code of conduct or rules regarding bullying and harassment? Yes or no?"
Ms Magill and her MIT and Harvard counterparts said repeatedly it would depend on the "context" and have been criticised for not flatly condemning any calls for the genocide of Jews.
The Congressional hearing was held amid widespread campus protests sparked by the Israel-Gaza conflict and a rising number of antisemitism incidents.
In a video statement released after the hearing, Ms Magill apologised for her testimony, but calls for her to step down have continued in recent days.
She was criticised by the White House, and a major donor who had planned to give the university $100m (£79.3m) pulled out, saying he was "appalled" at Ms Magill's comments.
On Thursday, two students at the university - both of whom are Jewish - filed a lawsuit, claiming the campus has become "an incubation lab for virulent anti-Jewish hatred, harassment and discrimination."
Ms Magill's resignation was confirmed by Scott L. Bok, chair of the Penn board of trustees. He said Ms Magill would step down as president but "will remain a tenured faculty member at Penn Carey Law".
Trustees had reportedly been due to meet on Sunday to discuss Ms Magill's position.
In a statement released via the university after her resignation was confirmed, Ms Magill said: "It has been my privilege to serve as President of this remarkable institution.
"It has been an honor to work with our faculty, students, staff, alumni, and community members to advance Penn's vital missions."
The University of Pennsylvania - commonly known as UPenn - is among the oldest and most prestigious universities in the US, and is part of the elite Ivy League group alongside institutions such as Harvard and Yale.