Mathieu J. Shapiro

Mathieu is the Managing Partner and General Counsel of Obermayer, as well as Co-Chair of the Litigation Department.  His practice focuses on appellate and business litigation, guided by a disciplined, client-centered approach that begins with a clear understanding of the client’s objectives and measures success accordingly.

In his appellate practice, Mathieu has briefed and argued matters before all levels of Pennsylvania’s appellate courts and in multiple federal courts, including the United States Court of Appeals for the Second, Third, and Seventh Circuits.  Leveraging his appellate experience, Mathieu works closely with trial teams to frame issues clearly, develop durable records, and present arguments designed to withstand scrutiny at every stage.

In his business-litigation practice, Mathieu represents businesses and individuals in complex disputes involving shareholder conflicts, fiduciary-duty claims, and sophisticated commercial contracts.  His role as Managing Partner brings an added dimension to his client representation.  By helping lead and operate a professional services organization himself, he understands firsthand the operational, financial, and strategic considerations that inform business decision-making—experience that shapes his pragmatic advice on risk, cost, and outcomes in litigation.

Mathieu is also the co-author, with the Honorable Paul S. Diamond of the United States District Court for the Eastern District of Pennsylvania, of the Director & Officer Liability chapter in the ABA’s Business and Commercial Litigation in Federal Courts treatise, a leading resource on complex federal litigation.

Outside the office, Mathieu enjoys cooking, traveling, skiing, and spending time with his wife and children.  A devoted Philadelphia sports fan, he is always hopeful for another championship parade.

Mathieu concentrates his practice in business and, commercial litigation, including all forms of contract disputes, “business divorces,” and family business disputes and employment litigation. He has represented large corporations and individuals in matters involving leases and real estate, non-competition agreements and restrictive covenants, breach of fiduciary duty, theft of proprietary information, partnership dissolution, shareholder disputes, data breaches, franchise agreements, U.C.C. interests, zoning, business torts, and insurance coverage.

Mathieu has also handles other complex matters, ranging from antitrust to civil rights, to FLSA class actions, and Orphans Court cases. In all of his cases, Mathieu manages trial and appellate work, including all phases of commercial litigation, from pre-litigation advice, pleadings, discovery, and dispositive motions, through trial or arbitration, and appeal. He has briefed and argued numerous appellate cases, in all of Pennsylvania’s appellate courts and in the 2nd, 3rd and the 7th Circuit United States Courts of Appeal. He has also worked on many class actions and multidistrict litigations. 

Some of Mathieu’s more notable cases include:

• Obtaining a seven-figure settlement for a manufacturing company that was a victim of accounting malpractice.
• Multi-million dollar settlements and injunctions on behalf of employers enforcing restrictive covenants and protecting valuable trade secrets.
• Obtaining favorable judgments and favorable settlements for companies accused of failing to prevent data breaches and failing adequately to protect confidential information.
• Obtaining favorable settlements, summary judgment and dismissal on behalf of several national and international financial institutions in matters related to alleged breach of contract, alleged agent misconduct, alleged bad investments, and alleged bad investment advice, as well as settlements over $500,000 representing individual customers against the institutions in regard to similar claims.
• Obtaining dismissals, change of venue and summary judgment on behalf of national companies involved in mergers and acquisitions who are sued by their shareholders for breach of fiduciary duty or aiding and abetting breaches of fiduciary duty, and violations of security laws.
• Obtaining favorable resolutions while representing numerous closely held or family businesses going through business divorces.
• A favorable settlement on behalf of a prominent insurance company in a state-wide class action related to discounts available in automobile insurance policies.
• A Pennsylvania Supreme Court reversal on behalf of a municipality and its mayor confirming the mayor’s right to appoint members to the local municipal authority.
• A favorable settlement on behalf of a school district and a local charter school in matters relating to statutory funding, Department of Education audits, and other litigation matters.
• Obtaining multiple summary judgments on behalf of a local Fortune 500 company in litigation regarding the constitutionality of a Pennsylvania statute restricting the successor-related asbestos liability of Pennsylvania corporations.
• Representing several well-known plaintiff law firms in litigation related to their break-ups, or their hiring of lateral partners from other firms.
• Representing a local professional sports franchise in a lawsuit against a municipality relating to the interpretation of the franchise’s stadium lease.
• Obtaining summary judgment for a local township in high profile civil rights litigations involving alleged discrimination in zoning procedures and in police conduct.

Many of Mathieu’s cases involve electronic discovery and digital forensic issues. In recognition of the growing importance of e-Discovery to his clients, Mathieu created Obermayer’s e-Discovery and Information Management Practice Group. A long-time proponent of “proportionality” in e-Discovery, Mathieu attempts to keep the costs of e-Discovery commensurate with the value of the case.

Mathieu, together with the Honorable Paul S. Diamond of the United States District Court for the Eastern District of Pennsylvania, is the author of a chapter entitled “Director & Officer Liability” in the critically-acclaimed ABA Section of Litigation treatise, Business and Commercial Litigation in Federal Courts, edited by Robert L. Haig (Thomson/West, 2021, 2011 and 2005 editions).

Mathieu was selected by peers for inclusion in The Best Lawyers in America® for Commercial Litigation from 2024 to 2026 and Pennsylvania Super Lawyers® for Business Litigation from 2022 to 2025.

Awards Won*

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