Sidne Koenigsberg

Sidne Koenigsberg

Counsel, Financial Institutions Regulation and Enforcement
Sidne Koenigsberg’s practice focuses on financial regulatory compliance and enforcement matters, including economic sanctions and anti-money laundering regulations, for French, U.S. and international clients.


Ms. Koenigsberg has worked with major international financial institutions on cross-border compliance and enforcement matters, including internal investigations; voluntary disclosures; and administrative, civil and criminal proceedings. She regularly advises clients on French banking secrecy and data protection laws in the context of such matters. She also counsels financial institutions and corporate clients on the development and implementation of compliance programs and related risk assessments and remedial measures. Additionally, she has developed and delivered training on U.S. and EU sanctions matters for compliance, legal and audit teams.

Ms. Koenigsberg also works with money services businesses and multinational companies on compliance matters, as well as due diligence and contractual representations regarding French and U.S. anti-money laundering and economic sanctions regulations in the context of corporate transactions. She also has assisted in the successful defense of an international financial institution and several of its senior executives in a U.S. class action securities litigation.

In addition, she has advised not-for-profit corporations, nongovernmental organizations and artists on a variety of pro bono matters.

Before joining Skadden, Ms. Koenigsberg worked for another international law firm in New York, advising private and public companies in general corporate matters, including mergers and acquisitions, financing and U.S. securities offerings.

As a Dean Acheson legal scholar, she served as a clerk for Judge Allan Rosas, the president of the Third Chamber of the Court of Justice of the European Communities.

Ms. Koenigsberg is part of the Skadden team ranked “Leading 1” (the top ranking) in the International and Internal Investigations category and “Excellent” in the Compliance Programs category by Décideurs magazine in 2018, 2019 and 2020. She has repeatedly been named as a Next Generation Partner by The Legal 500 EMEA.



  • J.D., Columbia University School of Law, 2006 (Symposium Editor, Columbia Journal of Law and the Arts; Harlan Fiske Stone Scholar)
  • B.A., Amherst College, 2003 (magna cum laude; Phi Beta Kappa)


  • New York
  • Paris


  • English
  • French

Sidne Koenigsberg

Counsel, Financial Institutions Regulation and Enforcement