The X Factor USA judge gave the money to the New York Daily News campaign, which is delivering supplies to those affected by the hurricane.
"I'm proud to give my support to the Daily News Sandy appeal," Cowell said. "This has been a terrible tragedy for so many families who have had their lives and homes destroyed."
He added: "I hope everyone gets all the help they need to put their lives back together as soon as possible."
Earlier, MTV announced that the cast of Jersey Shore will reunite for a special benefit to help the rebuilding effort in the show's hometown of Seaside Heights, NJ.
Ben Stiller, Alec Baldwin and Russell Crowe are among the stars that have offered their help, while ABC is today holding a 'Day Of Giving' to encourage viewers to donate to victims of the hurricane.
Meanwhile, NBC's telethon to help the relief effort raised more than $23 million (£14.4m) when it was held on Friday.