Catherine Yun

Member

Recent News:

Cozen O’Connor Promotes 31 Attorneys to Member and Senior Principal

“It’s always a pleasure to recognize the hard work and dedication of our attorneys and government relations professionals,” said Executive Chairman and Chief Executive Officer Michael J. Heller. “This outstanding class of new members and senior principals will undoubtedly propel Cozen O’Connor’s ongoing success.”

Catherine focuses her practice on white-collar defense and investigations, vigorously defending her clients’ rights. She offers strategic and practical solutions for companies and individuals facing a governmental inquiry and tackling whistleblower allegations.  She is a well-rounded and dedicated litigator, with substantial experience in both civil and criminal matters. Her white-collar expertise spans the False Claims Act (FCA), Foreign Corrupt Practices Act (FCPA), health care fraud, fraud conspiracy, bank fraud, and tax fraud. Catherine also provides civil litigation defense in both individual and class actions, in state and federal courts, and has defended clients in the most complex cases, including against antitrust multi-district litigation, RICO claims, and charges brought by federal regulators.

Prior to joining the firm, she served two years as a federal law clerk — first with the Honorable Ann Marie Donio of the U.S. District Court for the District of New Jersey, and next with the Honorable Gene E.K. Pratter of the U.S. District Court for the Eastern District of Pennsylvania. Prior to her clerkships, she practiced at an Am Law 50 international law firm. 

Catherine received her J.D. from the University of Pennsylvania Law School and her Bachelor of Arts, summa cum laude, in international studies and Asian American studies from Boston College. She holds a Certificate of Management from the Wharton School of the University of Pennsylvania. While at Penn Law, she externed for the New Jersey Office of Attorney General and appellate division of the Philadelphia Office of the District Attorney. 

Before launching her career as an attorney, Catherine worked at an international nonprofit organization. She maintains an active pro bono practice, representing indigent clients facing criminal charges in federal court and assisting clients in seeking expungement of their criminal records. 

Catherine serves on the Executive Committee, Justice Rising Advocates, for Community Legal Services of Philadelphia. Catherine also serves as a member of the firm’s Hiring Committee. She previously served as the co-chair of the Associates Committee. 

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Experience

News

Cozen O’Connor Promotes 31 Attorneys to Member and Senior Principal

March 20, 2025

“It’s always a pleasure to recognize the hard work and dedication of our attorneys and government relations professionals,” said Executive Chairman and Chief Executive Officer Michael J. Heller. “This outstanding class of new members and senior principals will undoubtedly propel Cozen O’Connor’s ongoing success.”

Catherine Yun and Damali Martin Elected to Executive Committee of CLS’s Justice Rising Advocates

December 06, 2023

PHILADELPHIA, Dec. 6, 2023 - Cozen O’Connor is pleased to announce that Catherine Yun and Damali Martin, attorneys in the firm’s Commercial Litigation Department, have been elected to the Community Legal Services of Philadelphia (CLS)’s Justice Rising Advocates (JRA) Executive Committee.

Publications

Notice of Appeal Summer 2024

July 15, 2024

A quarterly newsletter reviewing Third Circuit opinions impacting white collar defense lawyers

Notice of Appeal Spring 2024

April 09, 2024

A quarterly newsletter reviewing Third Circuit opinions impacting white collar defense lawyers

Notice of Appeal Fall 2023

October 10, 2023

A quarterly newsletter reviewing Third Circuit opinions impacting white collar defense lawyers.

Notice of Appeal Summer 2023

July 11, 2023

A quarterly newsletter reviewing Third Circuit opinions impacting white collar defense lawyers.

Notice of Appeal Spring 2023

April 18, 2023

A quarterly newsletter reviewing Third Circuit opinions impacting white collar defense lawyers.

US Supreme Court Confronts the Limits of Honest-Services Fraud

April 17, 2023

Stephen Miller and Cat Yun, attorneys in the firm’s White Collar Defense & Investigations group, authored an article in The Legal Intelligencer discussing the case of Percoco v. United States, where the Supreme Court must determine whether the honest-services-fraud statute applies only to public officials, or if it can apply to private citizens acting with influence over public officials.

Notice of Appeal Summer 2022

July 26, 2022

A quarterly newsletter reviewing Third Circuit opinions impacting white collar defense lawyers.

Notice of Appeal Spring 2022

May 02, 2022

A quarterly newsletter reviewing Third Circuit opinions impacting white collar defense lawyers.

Notice of Appeal Winter 2022

January 11, 2022

A quarterly newsletter reviewing Third Circuit opinions impacting white collar defense lawyers.

Notice of Appeal Fall 2021

October 08, 2021

A quarterly newsletter reviewing Third Circuit opinions impacting white collar defense lawyers

Doing Battle on (At Least) Two Fronts: What Happens When Multiple Regulators Engage in Parallel Enforcement Efforts?

July 20, 2021

Multi-agency cooperation efforts can go a long way toward obtaining mitigated civil or criminal penalties.

Notice of Appeal Summer 2021

July 13, 2021

A quarterly newsletter reviewing Third Circuit opinions impacting white collar defense lawyers

Notice of Appeal Spring 2021

April 13, 2021

A quarterly newsletter reviewing Third Circuit opinions impacting white collar defense lawyers

Notice of Appeal Winter 2021

January 12, 2021

A quarterly newsletter reviewing Third Circuit opinions impacting white collar defense lawyers.

High Court Examines Requirement of Political Party Affiliation for State Judges [The Legal Intelligencer]

December 04, 2020

Stephen Miller and Catherine Yun contributed an article to The Legal Intelligencer titled, "High Court Examines Requirement of Political Party Affiliation for State Judges." This article discusses a recent case that presents a challenge to the Delaware Constitution’s anti-patronage provisions

Notice of Appeal Fall 2020

October 19, 2020

A quarterly newsletter reviewing Third Circuit opinions impacting white collar defense lawyers.

Events & Seminars

Past Events

2023 PACDL White Collar Practice Seminar

November 16, 2023 - Philadelphia, PA

Education

  • University of Pennsylvania Law School, J.D., 2017
  • Boston College, B.A., summa cum laude, 2010
  • Pennsylvania
  • New Jersey
  • U.S. District Court -- Eastern District of Pennsylvania
  • U.S. District Court -- Middle District of Pennsylvania
  • U.S. District Court -- Western District of Pennsylvania

Honorable Gene E.K. Pratter, U.S. District Judge, Philadelphia, September 2019-2020

Honorable Ann Marie Donio, U.S. Magistrate Judge, Camden, N.J., September 2018-September 2019 

University of Pennsylvania Law School American Inn of Court, Member

Federal Criminal Law Committee for the Eastern District of Pennsylvania, Member 

Justice Rising Advocates Executive Committee of Community Legal Services of Philadelphia, Member (2023)