A swastika flag was hoisted above a New York University building named in honor of a billionaire philanthropist who has donated to Jewish causes.

Hundreds of students and parents spotted the symbols associated with Adolf Hitler’s Nazi Party on the purple and white flag — which also contained the letters “NYU” and the Star of David — during the university’s annual Grad Alley block party around 5 p.m. Wednesday, the university newspaper Washington Square News reported.

The flag was hoisted above NYU’s Steinhardt School of Culture, Education, and Human Development building, which overlooks Washington Square Park and has paid homage to philanthropists Michael and Judy Steinhardt since 2016.

Steinhardt and his wife, Judy, have donated to several Jewish causes — though she told the Bedford and New Canaan Magazine last year, “We are devoted to Jewish life and values, but we are not religious.”

“We are shocked and deeply troubled that this hateful symbol expressing antisemitism was raised on a flagpole overlooking Washington Square Park,” NYU spokesperson Wiley Norvell said in a statement.

“Campus Safety responded immediately to remove it and we are working closely with the NYPD to identify whoever is responsible.

“We are one community. We protect each other. And we will not let hate and division find a foothold on our campus.”

The flag was quickly taken down after around 15 minutes, but graduating students were left disturbed.

“It’s just disgusting, actually. Kind of repulsive,” senior Luca Pasquini told WCBS-TV.

Jiani Zou, a nursing graduate, described the flag as “hurtful.”

Hedge fund billionaire Steinhardt, who grew up in a Jewish home, is the founder of the Birthright Israel program — which provides free 10-day heritage trips to Israel for young Jewish adults between 18 and 26 – and told the Times of Israel in 2017 that “The modern state of Israel is the Jewish miracle of the 20th century.”

Steinhardt, who was described by Forbes as “Wall Street’s greatest trader” in 2014, is also the founder of the Steinhardt Foundation for Jewish Life and set up the Partnership for Excellence in Jewish Education, which saw 60 schools opened, the Jerusalem Post reported.

He was on NYU’s board of trustees for 27 years before he resigned in 2022 amid backlash over his antiquities scandal, which saw him surrender 180 looted antiquities worth $70 million.

In 2021, student government leaders called on university bosses to remove Steinhardt’s name from the Culture, Education, and Human Development building over the case.

Steinhardt, who donated $10 million to NYU, has not commented on the flag, but officials and students have been left outraged. The university settled a federal antisemitism lawsuit for an undisclosed amount in 2024.

NYU hosts its Grad Alley event the night before its All-University Commencement ceremony, which is held at Yankee Stadium.

Ahead of the event, ultra-woke students have been up in arms after it emerged that renowned social psychologist and bestselling author Jonathan Haidt — who has argued that Gen-Zers are coddled and anxious — will deliver the commencement speech.

School officials have branded Haidt one of the “most consequential scholars of the 21st century,” but a group of student government leaders say he doesn’t “accurately reflect the values and diversity” of NYU graduates.

The NYPD has been approached for comment.