The New York-born singer posted on her blog Wednesday that she is pledging the money on behalf of her parents and sister. She also said she "would not be the woman or artist that I am today" if it weren't for places like the Lower Eastside, Harlem, the Bronx and Brooklyn.
She writes: "Thank you for helping me build my spirit. I will now help you rebuild yours."
Superstorm Sandy made landfall more than a week ago, killing many of its more than 100 victims in New York City and New Jersey and leaving millions without power.
Lady Gaga added that New York is a place full of "relentless ambition."