Diane Welsh

Hon. Diane M. Welsh (Ret.)

JAMS Mediator, Arbitrator and Referee/Special Master

Case Manager
Brad McNamara
T: 215-246-9494
F: 215-246-0949
1717 Arch Street, Suite 3810, Philadelphia, PA 19103

Diane M. Welsh is available to conduct cases virtually. JAMS is equipped to provide virtual ADR services on a variety of online platforms, including Zoom, Microsoft Teams, WebEx, and more.


Hon. Diane M. Welsh (Ret.) is highly respected for her ability to successfully resolve disputes with sensitivity, patience, and persistence. As a U.S. Magistrate Judge for 12 years and since joining JAMS, she has mediated and arbitrated numerous class action/mass torts cases. Specifically, Judge Welsh has extraordinary skill in resolving high-stake multi-party disputes. Judge Welsh served on the Alternative Dispute Resolution committee for the United States District Court for the Eastern District of Pennsylvania for 10 years, drafting local federal court rules for court-annexed mediation program and she is a frequent speaker at Continuing Legal Education programs on settlement negotiation, mediation, and the ADR Act.

Representative Matters

  • Representative class action/mass tort disputes resolved by Judge Welsh include the following:
    • Case involving RICO allegations and alleged violations of federal and state consumer protection statutes brought by class of first time home buyers against Builder, Mortgage Broker, Appraiser, and Mortgage Lender. Plaintiffs claimed a fraudulent scheme to induce them to purchase homes with inflated prices with mortgages they could not afford
    • Presided over complex discovery disputes in the fen-phen diet drug litigation and mediated disputes between class counsel and trustees of the settlement fund
    • ERISA/Securities Fraud class action by former employees of major insurance company
    • Case involving RICO claims by class of owners of time shares in a resort property
    • Class action alleging violations of CERCLA and state law resulting from air and water contamination by pollutants; settlement reached for medical monitoring and property damage
    • Numerous wage-and-hour class actions brought in federal and state courts, including home healthcare workers, prison guards, poultry factory workers, and transit workers
    • Employment discrimination class actions brought by the U.S. Equal Employment Opportunity Commission
    • Mediated and served as Special Master in various securities class actions including claims against corporations, investment banks, underwriters, auditors, and research analysts
    • Numerous consumer class actions brought in federal and state courts including alleged violations of FCRA, FTPCA, TILA, RESDA, FACTA, FDCPA, and various state consumer protection statutes
    • Class actions against a public utility company for violation of state act for hazardous site cleanup seeking testing, remediation, and medical monitoring
    • Class action against a technology company, the county and sheriff for release of confidential information relating to applicants for gun permits; the technology contractor allowed gun permit lists and personal information of 25,000 permit holders to be unprotected and accessible via the internet
    • Various class actions against insurance companies involving claims handling and payments
    • Employment actions alleging discrimination in promotions and salaries, including telecommunications manager, transit supervisors, and chemical company technicians
    • Consumer class action against automobile manufacturer alleging breach of warranty of the brake system
    • Collective actions involving property damage caused by asbestos
    • Class action alleging personal injury caused by silica exposure
  • Completed Virtual ADR training conducted by the JAMS Institute, the training arm of JAMS
  • Listed as a "Recognized Practitioner," Chambers USA, 2019
  • Recognized as an “ADR Champion”, National Law Journal, 2016-2018
  • Voted “BEST ADR INDIVIDUAL” by the readers of ALM’s Legal Intelligencer, Best of 2007-2016
  • Recognized as Mediation "Lawyer of the Year", Philadelphia, Best Lawyers in America, 2014
  • Recognized as a Best Lawyer, Alternative Dispute Resolution Category, Best Lawyers in America, 2007-2022
  • Recognized as a Pennsylvania Super Lawyer, Alternative Dispute Resolution Category, Law & Politics Magazine, 2008-2009
  • Voted "Best Individual Mediator", National Law Journal, "Best Of" Survey, 2012
  • Member, Federal Magistrate Judges Association; Third Circuit Director, 1999-2004
  • Member, The Forum of Executive Women
  • Member, American Inns of Court; President, Temple American Inn of Court, 2002-2003
  • Member, National Association of Woman Judges, Federal Bar Association, Montgomery Bar Association, Philadelphia Bar Association,
  • Bucks County Bar Association, Pennsylvania Bar Association, and other professional organizations
  • Member of Third Circuit and U.S. District Court for the Eastern District of Pennsylvania court committees, including Federal-State
  • Judicial Council, Committee on Bankruptcy and Magistrate Judges, Alternative Dispute Resolution Committee, Court Interpreters
  • Committee, Bench Bar Public Relations and Educational Programs Committee, and Congressional Delegation Committee
  • U.S. Magistrate Judge, U.S. District Court for the Eastern District of PA, 1994-2005
  • Private Law Practice, 1984-1994
  • Deputy District Attorney, Bucks County District Attorney’s Office, 1981-1984
  • Legal Counsel, Pennsylvania Senate Judiciary Committee, 1980-1981
  • J.D., Villanova University School of Law, 1979
  • B.A., Political Science, Magna Cum Laude, La Salle University, 1976

Counsel Comments

    • “Judge Welsh was excellent in her command of the issues and her willingness to lead the parties. She was efficient in methods of sharing proposals to resolution. She was a great and skilled neutral.”
    • “We were extremely impressed by Judge Welsh's command of Zoom and the initiative she took in getting the parties to communicate one-on-one more often during the mediation. We always appreciate the Judge's commitment to reaching a resolution day-of and her focus on the practical outcomes that could be reached.”
    • “Judge Welsh was excellent. She clearly did her homework and read all the materials provided to her in advance and was very knowledgeable about the issues. I cannot imagine any other mediator getting the result we did in that short of time. A very successful day.”
    • “Mediator Diane Welsh was extremely well prepared, effective and brokered a very fair result for both sides.”
    • “She is a superb settler of cases. She is tenacious, persistent and imaginative.” 

      - Almanac of the Federal Judiciary
    • “In complicated civil cases, she is very impressive.” 

      - Almanac of the Federal Judiciary
    • “Very few judges could settle the cases she can settle because they don’t take the time to understand them.” 

      - Almanac of the Federal Judiciary
    • “She is balanced. She goes out of her way to demonstrate to each party that she is not biased toward either party.” 

      - Almanac of the Federal Judiciary



Practice Areas

  • Antitrust
  • Arbitration
  • Aviation
  • Business/Commercial
  • Civil Rights
  • Class Action/Mass Tort
  • Construction Defect
  • Education/Schools
  • Employment
  • Entertainment and Sports
  • Environmental
  • Federal Judge
  • Financial Markets
  • Governmental/Public Agency
  • Insurance
  • Intellectual Property
  • Life Sciences
  • Maritime/Admiralty
  • Personal Injury/Torts
  • Product Liability
  • Professional Liability
  • Real Property
  • Securities
  • Surety
Available nationwide


This page is for general information purposes.  JAMS makes no representations or warranties regarding its accuracy or completeness.  Interested persons should conduct their own research regarding information on this website before deciding to use JAMS, including investigation and research of JAMS neutrals. See More

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