WASHINGTON—President Trump will nominate Nellie Liang, a former Federal Reserve economist who created its first office of financial stability, to the central bank’s board of governors, the White House said Wednesday.

In 2010, then-Fed Chairman Ben Bernanke tapped Ms. Liang to form the office to oversee risks in the financial system in the wake of the 2008 crisis. Today, that operation is as large as the Fed’s long-dominant division of monetary affairs.

Ms....