Calum Warren
Calum Warren is a partner in Matheson’s Competition and Regulation Group. Prior to joining Matheson, Calum worked at leading international law firms in Brussels and London. With over 15 years’ experience, Calum is a leading advisor on all aspects of Irish and EU competition and regulatory law, including M&A regulatory clearances, competition compliance, investigations and litigation, sectoral regulation and general EU regulatory law, public procurement and State aid. Calum is at the forefront of advising on the new Irish FDI screening regime and co-leads Matheson’s Foreign Investment Screening group.
Publications
Co-author of the Ireland chapter in the Merger Control Law Guide , published 14 July 2026 , alongside Niall Collins , Kate McKenna and Simon Shinkwin .