According to a university spokesperson, the students reported being robbed at gunpoint by two suspects. The students were not injured, but had personal items stolen.
It happened in the area of 1939 Hall, a residential building on campus.
Princeton police responded to assist the university's department of public safety.
It wasn't hard to find Princeton University students who heard about the armed robbery early Sunday morning.
"I woke up pretty early and I heard about it. It was a little bit concerning," said freshman Rishi Khanna.
"And then the campus went into lockdown for a few hours while they looked for whoever it would've been," said senior Sam Grayson.
The lockdown was lifted a few hours later.
Grayson says she doesn't normally walk around campus in the overnight hours for safety reasons anyway. While she isn't alarmed by the incident, her mother definitely was.
"I think the parent group chat freaks out whenever something strange happens," said Grayson.
An alert also went out to the neighboring Princeton Theological Seminary.
"I think for security, they were just keeping us in the loop," said Karl Bjorkman, a student at the seminary.
Folks we spoke with say a robbery on campus is very unusual.
"You know we didn't have any of this kind of stuff going on so clearly things are a little more dangerous," said Kash Rg, a former Princeton student.
Extra safety patrols have been added on campus in light of the incident.
Anyone with information should contact the university department of public safety.