The Act will come into force on 1 April and will see the Financial Services Authority broken up to create the Financial Conduct Authority, Prudential Regulation Authority and the Financial Policy Committee.
The Royal Assent marks the end of a two and a half-year process first set out by chancellor George Osborne in his Mansion House speech in June 2010.
Financial Secretary to the Treasury Greg Clark says: “The Financial Services Act replaces a regulatory structure which palpably failed when tested by crisis.
“It sets out a comprehensive regulatory framework designed to enhance financial stability in the future and protect consumers. It takes important steps to focus the regulators on rebuilding competition in a banking sector that has become too concentrated.”