Mary Aileen O’Callaghan


  • Loyola University School of Law, J.D., 1977
  • Associate Editor Loyola University Law Journal, 1976-1977
  • Mundelein College, B.F.A., with honors, 1967

Practice Areas

  • Labor and Employment Law
  • Employment Counseling
  • Administrative Agency Proceedings
  • NLRB and Labor-Management Relations
  • Preparation of Affirmative Action Plans/OFCCP Proceedings


  • Adjunct Professor, Loyola University of Chicago School of Law, 1980-1983
  • Adjunct Faculty, University of Wisconsin Management Institute, 1991-1998


  • Illinois, 1977
  • U. S. District Court, Northern District of Illinois, 1988
  • U. S. District Court, Northern District of Illinois Trial Bar, 1996
  • U. S. District Court, Central District of Illinois, 1990


    • American Bar Association

    • Section of Labor and Employment Law
    • Equal Employment Opportunity Law Committee
    • Employee Rights and Responsibilities Committee
    • International Labor Law Committee
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Mary Aileen O’Callaghan

Mary Aileen O’Callaghan is a partner with Smith O’Callaghan & White. She has more than 30 years of experience in the practice of labor and employment law. Prior to joining the firm, Ms. O’Callaghan was in-house counsel for labor and employment matters with a Global 500 corporation and a partner with a prominent labor and employment law firm in Chicago. Ms. O’Callaghan was inducted as a distinguished Fellow in the College of Labor and Employment Lawyers in 1998, a recognition reserved for the most experienced and prominent labor and employment attorneys in the United States, and was selected as an Illinois SuperLawyer each year from 2005-2015.

Ms. O’Callaghan was named one of the top 50 women lawyers in Illinois for 2010 and 2012 by SuperLawyers magazine. In addition, she has been recognized by her peers as a Leading Lawyer in the category of Employment Law: Management. Ms. O’Callaghan holds the AV® Preeminent Peer Review Rating, Martindale-Hubbell’s highest rating for ethics and legal ability.

Ms. O’Callaghan counsels employers concerning all aspects of employment law, including the ADA, the FMLA, workplace harassment, reductions-in-force, plant closings, compliance with the Older Workers Benefit Protection Act and the Worker Adjustment Retraining and Notification Act, EEO and diversity training, wage and hour compliance, internal discrimination and harassment investigations, and administrative agency investigations and proceedings. She is one of the country’s most experienced practitioners in the area of affirmative action; she has prepared and successfully defended affirmative action plans in the public and private sectors for 30 years. Ms. O’Callaghan also maintains an extensive practice in the traditional labor law area. She has assisted clients in more than 200 NLRB representation elections, achieving a success rate in excess of 98 percent. She works with employers to deal with day-to-day human resources decisions and provides counsel to ensure compliance with all state and federal labor and employment laws.

Recognition & Awards

  • Fellow, College of Labor and Employment Lawyers, inducted 1998
    See All Awards
  • Recognized as one of the Top 50 Women Lawyers in Illinois
    by Super Lawyers magazine for 2010 and 2012
  • Named Illinois Super Lawyer
    in Labor and Employment Law,
    Chicago magazine

  • AV® Preeminent Peer Review Rating from Martindale-Hubbell
    Highest rating for legal ability and ethics
  • Recognized by peers as a Leading Lawyer
    Employment Law: Management, 2009-2017
    Law Bulletin Publishing Company
  • Experience as in-house labor and employment counsel
    with legal department of Global 500 corporation
  • Founding Partner of Smith O’Callaghan & White,
    January, 2000


“Labor Law-Ominous Implication for Public Sector Collective Bargaining in Illinois,”
8 Loy. Chi. L.J. 209 (1976).

“Employment Discrimination Law,”
2d edition, 1983-1985 cum. supplement, BNA Books, 1987-1990 (Contributing Editor).


Council on Education in Management, Speaker

Executive Enterprises, Speaker

American Bar Association, Section of Labor and Employment Law, Mid-Winter Meetings, Speaker

American Management Association, Speaker

Reported Decisions

McEwen v. Delta Air Lines, Inc., 919 F.2d 58 (7th Cir.) (Precedent-setting case on standard used for summary judgment in retaliatory discharge cases in federal court on diversity, and affirming summary judgment in favor of employer).

Kohnke v. Delta Air Lines, Inc., 932 F. Supp. 1110 (N.D. Ill.) (ADA case analyzing the application and scope of the “direct threat” defense).

Taylor v. Canteen Corp., 789 F. Supp. 279 (C.D. Ill.) (Case considering oral contract and promissory estoppel claims brought by a supervisory, at-will employee).