Tonianne Florentino

Tonianne Florentino

Collazo Florentino & Keil llp
747 Third Avenue, New York, NY 10017-2803
P: 212-758-7782
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Ms. Florentino has more than 25 years of experience practicing employment and labor law. She is currently a partner at boutique labor and employment law firm Collazo Florentino & Keil LLP.  She was formerly Counsel to Simpson Thacher and Bartlett, where she spent thirteen years. At the start of her legal career, Ms. Florentino served as a law clerk to the Honorable Lawrence W. Pierce, in the Second Circuit Court of Appeals.

Ms. Florentino represents employers in a wide variety of industries including health care, financial services, media, airline, and not-for-profit organizations. She regularly represents and advises both non-union and unionized companies with respect to: employment and labor relations issues; compliance with federal, state and local labor and employment laws; discrimination and other employment-related litigation and administrative proceedings; employment contracts and separation agreements; FMLA and other leaves of absence; employment contracts, separation agreements, and commission agreements. A substantial portion of her practice involves counseling employers on a day-to-day basis on ways to avoid litigation in connection with difficult business decisions such as terminating long-term employees, responding to harassment complaints; advising on challenging grievance issues and preparing for reductions in force or other changes in the workplace. Ms. Florentino also regularly conducts training on such topics as the prevention of discrimination and harassment; drug-free workplace enforcement, successful outsourcing and conducting performance appraisals. Given the significant costs of litigation, Ms. Florentino is an advocate of preventive measures including strategic business planning, training, and customized policies.  When litigation arises or is threatened, Ms. Florentino often counsels clients on a range of responses, including alternative dispute measures. In addition to her practice in advising and representing employers with regard to employment and traditional labor law matters, Ms. Florentino has considerable experience in conducting workplace investigations involving a wide variety of issues, including harassment and workplace theft.

Ms. Florentino is a member of several bar associations and has written numerous publications on labor and employment law, including Privacy in the Workforce, 2004 PLI Fifth Annual Institute on Privacy Law, and Workplace Privacy in the Technology Revolution; 2001 PLI First Annual Institute on Privacy Law.


  • St. John’s University Law School, J.D., 1986;
    • St.Thomas More Scholar
    • Editor-in-Chief, St. John’s University Law Review, (1985 - 1986)
  • New York University Robert F. Wagner Graduate School of Public Service, M.P.A., 1983
  • Queens College, B.A., 1980


  • New York, 1987 
  • U.S. Court of Appeals, Second Circuit, 1999
  • Southern District of New York, 1988
  • Eastern District of New York, 1988
  • Northern District of New York, 1988
  • District of Arizona, 1990 
  • Eastern District of Michigan, 1990