Gaga, 27, is paying USD 22,000 per month for the 1,985-square-foot duplex, reported the New York Times.
The mansion has two giant bedrooms, a granite chef's kitchen, a wood-burning fireplace, a large marble bathroom and a view of Central Park.
Gaga is said to have moved into the locale about a month ago.
"It's so cool! She comes and goes with all this security. I can't believe she's my neighbor," a source said.