Music producer Timbaland (real name Timothy Zachery Mosley) joined the couple, who married in Italy last month.
The neighbourhood of Far Rockaway was heavily damaged by floodwaters and many in the community are still without heat and electricity two weeks after the storm.
"Shout out to Justin Timberlake and Jessica Biel for serving alongside of us in Rockaway and giving the kids something to talk about besides Sandy," local resident Jessica Nortesano tweeted, sharing a photo of the couple unloading a truck.
The celebrity couple previously tweeted their good wishes to those affected by the hurricane.
"Taking in the devastation caused by Hurricane Sandy," wrote the 31-year-old SexyBack singer, while Jessica added: "Sending my prayers and love to New York City and to everyone affected."