
Guillermo Matías Osorio

Labor & Employment

"Up-and-coming partner Guillermo Osorio routinely represents major companies in complex labour litigation proceedings involving claims brought by senior-level employees."
Chambers Latin America, 2024
Guillermo M. Osorio joined Marval O’Farrell Mairal in 2009 and has been a partner in the Labor and Employment Law Department since 2019. He is part of the litigation team specializing in complex employment lawsuits that manages a portfolio of high-profile lawsuits, primarily disputes with executives, directors, and expatriates. Over the past decade, the team has defended multinational companies in a portfolio valued at over USD 600 million, including Argentina's most economically relevant individual labor law trial. He also provides advice from the labor perspective on mergers, due diligences, complex compensation structures, hires, and sensitive and massive terminations.
At the same time, he is a member of the Firm's Strategic Innovation Committee, which has developed various technological solutions for the management of claims and lawsuits.
Guillermo graduated from Universidad de Buenos Aires with a law degree in 2007. Afterwards, he completed multiple postgraduate degree courses at the Pontifical Catholic University of Argentina (Specialization in Labor Law) and Torcuato Di Tella University (Complex Litigation and Labor Complex Litigation before the Supreme Court of Justice). He also completed multiple continuing education courses at Asociacion Argentina de Derecho del Trabajo y la Seguridad Social. And in September 2020, he completed the Harvard University’s CS50 for Lawyers course. In addition, he taught courses on strategic planning for labor trials at the San Isidro Bar Association.
He is a member of the City of Buenos Aires Bar Association and the San Isidro Bar Association.