Sigal Pearl Mandelker (born 1971) is an American lawyer who served as Under Secretary of the Treasury for Terrorism and Financial Intelligence from 2017 to 2019.

She was Counselor to the Secretary of Homeland Security before she worked in the Criminal Division of the Department of Justice as Deputy Assistant Attorney General.

In 2008, while in the criminal division of the Department of Justice, Mandelker was part of the team of high ranking DOJ officials who agreed not to pursue federal charges against sexual predator Jeffrey Epstein.

[8] The deal allowed Epstein to spend only about a year in jail and plead guilty only to state crimes, avoiding federal charges entirely.

Included in these sanctions were those applied in 2017 and again in 2018 against billionaire Dan Gertler and his companies as a result of his "opaque and corrupt" mining and oil deals in the Congo.

These sanctions severely limited his global business acumen as he was refused access to the US banking system and other financial institutions concerned with violating American law.