Nancy Killefer (1953- ) is an American government consultant and political figure. She was nominated for the Chief Performance Officer presidential cabinet position in the Obama administration in 2009. In 2005 the District of Columbia government had filed a more than $900 tax lien on her home for failure to pay state unemployment tax on household help. She resolved the matter five months after the lien was filed. Killefer withdrew her nomination as CPO on February 3, 2009.

Nancy Killefer was a Senior Director and Head of the Washington, D.C., office of McKinsey & Company, the global management consultancy. She left McKinsey & Company from 1997 to 2000 to serve as Assistant Secretary for Management, CFO, and COO at the United States Department of the Treasury. After returning to McKinsey in 2000, she joined the IRS Oversight Board, a public-private entity akin to a corporate board that oversees the IRS. She served there from 2000 to 2005 and was its Chairperson from 2002 to 2005.

Killefer received her M.B.A. from the Sloan School of the Massachusetts Institute of Technology. She holds a B.A. with honors in economics from Vassar College. Prior to business school, Killefer worked as an associate at Charles River Associates, a microeconomics consulting firm. Grand daughter of long time major league baseball catcher and manager Bill Killefer.