Karen Gillen


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Karen Gillen is an experienced litigator representing employers in class, representative and collective actions, and single and multi-plaintiff lawsuits in employment matters. Her litigation practice focuses on a broad range of employment law issues including wage and hour, ERISA, discrimination, retaliation, and wrongful termination. She also focuses on litigating breach of employment contract and restrictive covenant disputes. Karen regularly represents employers before administrative agencies including the Equal Employment Opportunity Commission, the New York State Division of Human Rights, the New York City Commission on Human Rights, and other state and local administrative agencies.


Honors & Awards

  • Recognized in the Best Lawyers in America for work in Employment Law – Management, and Litigation – Labor and Employment (2019)


Bar Admissions

  • New York
  • New Jersey
  • Arizona

Court Admissions

  • US District Court, District of Arizona, District of New Jersey, Eastern District of New York, and Southern District of New York
  • US Court of Appeals, Fifth and Ninth Circuits


  • Arizona State University, Sandra Day O’Connor College of Law, J.D.; magna cum laude, Arizona State University Law Review
  • Rutgers University, B.S., Accounting; with highest honors

Professional Activities


  • Honorable Philip E. Toci, Arizona State Court of Appeals


  • New York City Bar Association
  • New Jersey Bar Association, Aviation Law Committee
  • Society for Human Resource Management
  • New York City Society for Human Resource Management
  • Valley of the Sun Human Resources Association, Past Member of the Board of Directors.
  • Prior Judge Pro Tempore, Maricopa County Superior Court


  • “Pink Slipped Employees Seeing Red,” NewsLedger (July/August 2001)

Contributing Author

  • “The Fair Labor Standards Act” (Ellen C. Kearns ed.), 2005 Cumulative Supplement, a BNA publication
  • “Wage and Hour Laws: A State-By-State Survey (Gregory K. McGillivary, ed., 2005), a BNA publication
  • Previous contributing author to “Ask the Experts” column, The Arizona Republic


  • Commentator, 73rd Annual NYU Conference on Labor
  • Presenter, “Precedents and Predictions: A Review of 2020’s Significant Labor and Employment Law Developments and What to Expect in 2021 – New York”
  • Presented on numerous occasions on employment law issues at the State Bar of Arizona’s CLE By-The-Sea programs
  • Frequent presenter on employment law issues
  • Successfully opposed class certification in a lawsuit alleging that a defined benefit plan’s older mortality tables used to calculate a retiree’s joint and survivor annuity resulted in a substantially lower retirement benefit than would be received if the plan used updated mortality tables.
  • Defeated a summary judgment motion filed by the Massachusetts Attorney General in a case challenging the application of the Massachusetts Earned Sick Time Law as applied to airlines.
  • Obtained summary judgment on behalf of a corporation and its fiduciaries in a lawsuit alleging that an option in the corporation’s 401k plan violated ERISA and represented the corporation and its fiduciaries on appeal, where summary judgment was affirmed.
  • Successfully defended employers on numerous occasions in labor and employment arbitrations.
  • Obtained dismissal of charges and negotiated favorable outcomes before a variety of administrative agencies including the Equal Employment Opportunity Commission, the New York State Division of Human Rights and the New York City Commission on Human Rights.
  • Represented American Airlines in a gender equity putative class action.
  • Led the American Airlines employment law team through the merger with US Airways that created the world’s largest airline.