Jillian L. Seifrit

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

Office: (267) 930-4651


Widener University Delaware Law School
Juris Doctor, magna cum laude

Pennsylvania State University
Bachelor of Arts, Political Science


  • Pennsylvania
  • New Jersey

Practice Areas

Professional Memberships

  • Philadelphia Bar Association

Jillian Seifrit is a Partner at Mullen Coughlin who counsels organizations who have a real, or suspected, data privacy and security incident occur. With industry experience in telecommunications, life sciences, chemicals, energy and financial services, Jillian is called upon to assist organizations in these industries with investigating data privacy and security incidents, responding to regulatory investigations and determining notification obligations based on state, federal and international law, contractual obligations and industry-specific requirements.

Before joining Mullen Coughlin, Jillian was a Senior Associate at a “Big Four” accounting firm practicing in their state and local tax service area. There she focused on state tax due diligence projects for large-to-medium-sized businesses across multiple sectors. In addition, she worked on state tax controversy and state tax structing projects.

While in law school, Jillian was an editor of the Widener Law Review and graduated magna cum laude.

Outside of the firm, Jillian is a member of the Bethesda Project’s “Young Professional Advisory Board.” The Bethesda Project is a Philadelphia-based non-profit organization that provides emergency shelter, housing and other supporting services for homeless individuals and families across Philadelphia.