Guillermo Sánchez de Miquel has been a principal associate in Garrigues’ Administrative Law Department since 2024, after joining the firm in 2013.

He has a wealth of experience in all aspects of EU and antitrust law, as well as FDI/National Security in Spain. In particular, Guillermo regularly participates in:

• Administrative and judicial review proceedings related to cartels and national and international breaches of antitrust law.
• Merger filings before the national and European antitrust authorities.
• FDI/National Security filings before the Spanish authorities.
• Analysis of vertical and horizontal agreements.
• Compliance and internal training processes for companies in connection with antitrust law.
• Cases involving state aid and subsidies.

Guillermo also has vast experience in all the different areas of administrative law, in judicial review proceedings and planning and zoning law. He provides recurring advice both to private and public entities in all types of proceedings before the public authorities, in administrative proceedings and judicial review appeals. He regularly participates in:

• Judicial review appeals involving planning and zoning.
• Infringement proceedings and proceedings to restore planning and zoning compliance.
• Drafting, providing advice on and processing of planning instruments.
• Drafting, providing advice on and processing of zoning management instruments (reallotment plans etc.).
• Planning and zoning due diligence reviews.
• Public procurement advice.

Guillermo also has extensive experience across the different areas of Administrative Law and Administrative Litigation. He advises on a wide range of sector-specific Administrative Law matters, including, among others, defense, pharmaceutical, construction, funeral services, infrastructure, and urban planning.

He also provides ongoing advice in all these fields, mainly though continuous analysis according to each client’s needs, providing strategic preventive and reactive bespoke advice to clients.

• Law degree, Universidad Pompeu Fabra, Barcelona.
• Law degree, Università degli Studi Roma Tre, Rome.
• Master’s Degree in Access to the Legal Profession, Universidad Pompeu Fabra, majoring in public law.

Guillermo has been an associate lecturer in the Administrative Law Department of the Law Faculty of Universidad de Barcelona (UB) since 2019, where he teaches the modules: “Legal Regime and Common Administrative Procedure” and "Public Property and Urban Planning".

Since 2022, he has also been an associate lecturer at Instituto Superior de Derecho y Empresa (ISDE), where he teaches "Procedural Law in the European Union" in the Master’s Degree in International Legal Practice and Business.

Guillermo also teaches Antitrust law in the Master’s Degree on public procurement at Universidad de Barcelona.

Guillermo Sánchez de Miquel is a member of the Barcelona Bar Association (ICAB) and of the Spanish Antitrust Association (AEDC). 

Guillermo has been included in the "Ones to Watch" in Spain 2024, 2025 and 2026 list by "Best Lawyers", in the category Administrative Law.