Congress gave the measure its final approval late Monday. Obama signed it Tuesday night, minutes after returning to the White House from a visit to Nevada.
It took Congress three months after Sandy devastated areas along the East Coast to approve the emergency funding. Obama scolded lawmakers for delaying recovery efforts even as he commended them for providing the long-awaited aid.
Conservatives concerned about billions in debt opposed the measure. Earlier this month, House Republicans removed unrelated spending from the bill.
The Oct. 29 storm was one of the worst to strike the Northeast and is blamed for more than 130 deaths and tens of billions of dollars in property damage.