Launching today, the DraftKings Brackets product offers a free-to-play game with $64,000 available in prizes and a $100,000 bracket for New Jersey customers that pay $20 to enter.
Customers can join public leagues or create their own private contests and interactive play will be available in the rounds of 32 and 16.
Matt Kalish, DraftKings Chief Revenue Officer and Co-Founder, said: "As American sports fans during March Madness, we are all playing bracket contests with our friends, family and co-workers.
"By launching Brackets on DraftKings Sportsbook, we are bringing the number one way fans engage with March Madness to the biggest stage."
March Madness is one of the hot topics in US sports betting; rival operator FanDuel has announced the opening of its Valley Forge Casino sportsbook, in Pennsylvania, in time for the tournament.