Ellyce R. Cooper

ELLYCE COOPER serves as a co-leader of the firm’s globally recognized Crisis Management and Strategic Response team and helps assists companies across industries facing significant crises and government investigations. She guides companies in developing comprehensive, thoughtful, and responsive strategies. Ellyce is adept at handling multi-faceted matters involving numerous government and regulatory agencies and parties. Ellyce’s diverse white collar experience includes representing clients in internal investigations and high-profile government-facing investigations involving the Department of Justice (DOJ) and the Securities and Exchange Commission (SEC).

Ellyce also has extensive experience handling complex civil litigation and is a member of Sidley’s Consumer Class Actions and Corporate Governance practices. Ellyce’s clients include notable companies in the technology, healthcare, pharmaceutical, accounting, financial, defense, and automotive industries. Ellyce’s practice includes representing clients in matters involving trade secret theft, sanctions, fraud and False Claims Act matters, and investigations. She has defended clients through various stages of litigation, from trial preparation through verdict, including in a significant ongoing matter pending trial.

Ellyce is recognized as a notable practitioner in Chambers Crisis and Risk Management both in the U.S. and globally, and is also ranked in Chambers USA (2022–2025) for California Litigation: White-Collar Crime & Government Investigations, with clients noting:

• “Ellyce is extremely knowledgeable, thorough, and organized. She gains the confidence of her clients by way of her excellent advice and client-centric approach” (2023).
• “As a client, I trust her wholeheartedly with each matter. Her advice is always well reasoned and thoughtful, and reflects her deep understanding of her clients and their businesses” (2023).
• “She is a pure delight to work with. She does a fantastic job at navigating complex issues and protecting the interests of her clients” (2023). 
• “She is just phenomenal. She is an extremely knowledgeable person - when she gets a case, she knows the facts backwards and forwards and has an encyclopedic knowledge of the facts” (2023).

L.A. Biz named her as one of their 2019 “Women of Influence,” a list recognizing women who have found success in a range of businesses affecting the Los Angeles economy while also making time to mentor younger executives, work with nonprofit organizations and pursue charitable endeavors. She has also been recognized by Best Lawyers in the category of Criminal Defense: White-Collar (2018–2022).

Ellyce regularly writes and speaks on topics relating to crisis management.

• Representation of a leading automotive manufacturer in multidistrict litigation involving allegedly faulty airbags. Negotiated a favorable settlement for our client with the consumer plaintiffs. This case involved the largest vehicle recall in history.
• Representation of a medical device company in connection with a DOJ investigation related to FDA regulatory issues.
• Representation of a multinational pharmaceutical company in connection with a joint civil and criminal investigation by the U.S. Attorney’s Office for the Central District of California and the DOJ’s Consumer Protection Branch and Civil Fraud Section concerning allegations of off-label promotion.
• Representation of a pharmaceutical company in preparation for an FDA audit.
• Representation of accounting firms in SEC inquiries involving the mortgage industry and stock options.
• Representation of clients in government inquiries and internal investigations involving bribery and the Foreign Corrupt Practices Act (FCPA).
• Advising a financial institution concerning inquiries by the FTC and the Consumer Financial Protection Bureau.
• Representation of various financial institutions in connection with DOJ investigations.

• Ellyce serves as Century City Inclusion Committee Partner Co-Chair.
• Ellyce serves as a firmwide co-leader for SidleyWomen.
• Ellyce is a proud member of the Geffen Playhouse Advisory Board. She is a member of the Women’s White Collar Defense Association (WWCDA) and is a Fellow of the American Bar Foundation.
• She is well-versed in electronic collection and production, and is a speaker on internal investigations, whistleblower-related topics and electronic discovery.  
• Ellyce serves on the firm’s Risk Management Committee. She previously served as co-chair of the Greater Los Angeles Committee for the Retention and Promotion of Women where she developed several innovative programs. She also previously served on the Summer Associate and Recruiting Committees for several years.

Ellyce is part of a team working alongside pro bono partner Public Counsel that sought a preliminary injunction requiring the government to provide mental health services to a putative class of immigrant families separated upon entry into the United States. On November 6, 2019, in a groundbreaking 50-page order, Judge Kronstadt of the U.S. District Court for the Central District of California granted the preliminary injunction and certified the class, requiring mental health screenings and treatment to help separated family members begin to address the severe and ongoing trauma associated with family separation. Public Counsel honored the team with its 2019 Pro Bono Award in recognition of Sidley’s efforts on this matter.