WASHINGTON—Michael Barr, a former Treasury Department official, is the White House’s leading candidate to serve as the Federal Reserve’s top banking regulator, according to people with knowledge of the Biden administration’s internal deliberations.

Mr. Barr was assistant treasury secretary for financial institutions during the Obama administration. In that role, he helped craft the 2010 Dodd-Frank Act, a sweeping overhaul of financial regulation that followed the 2008-2009 financial crisis.