Marielle C. Montecillo

426 W. Lancaster Avenue, Suite 200
Devon, PA 19333

Office: (267) 930-4675


Villanova University Charles Widger School of Law
Juris Doctor

Seton Hall University
Bachelor of Science, Diplomacy & International Relations and Economics, cum laude


  • Pennsylvania

Practice Areas

Marielle Montecillo is an Associate at Mullen Coughlin and assists organizations with investigating and responding to data privacy and security incidents. After an incident, such as a data breach, has been identified, Marielle works closely with the organization in determining the nature and scope of the incident and coordinates with forensic investigators, law enforcement, regulatory agencies and other third parties to ensure that the incident is fully investigated and day-to-day business is minimally interrupted. She also counsels victim organizations on their legal and regulatory obligations and works to ensure that they are compliant with all respective laws, statutes and industry standards or requirements.

Marielle joined Mullen Coughlin from a multinational e-commerce company, where she acted as in-house counsel specializing in data privacy and security. Before working in data privacy, Marielle was a tax associate at a top-rated public accounting firm. There, she researched and wrote on various tax issues related to state and local tax and mergers and acquisitions.

While a law student at Villanova University, Marielle was in the “Student Honors Program” in the U.S. Securities and Exchange Commission’s (SEC) Division of Enforcement. She also interned for the Vanguard Group and served as the Managing Editor of Citations & Sources for Villanova’s Jeffrey S. Moorad Sports Law Journal.