The hearings will be held in September and October in Washington, Chicago and San Francisco.
The Fed also announced that it will extend the public comment period on the deal through October 12.
The Fed said the hearings will help it determine if the deal will "produce benefits to the public" that "outweigh possible adverse effects, such as undue concentration of resources, decreased or unfair competition, conflicts of interests, unsound banking practices, and risk to the stability of the U.S. banking or financial system."
Some consumer groups and members of Congress have called on the Fed to further scrutinize the deal.
Capital One agreed in June to buy ING Direct from the Dutch banking and insurance group for $9 billion in stock and cash. ING had to sell the business, one of the jewels of its retail banking franchise, as part of a deal with the European Commission following its October 2008 Dutch government bailout.
(Reporting by Dave Clarke, Editing by Carol Bishopric)