J. Thad Heartfield

Professional Summary: J. Thad Heartfield

J. Thad Heartfield is an intellectual property litigator with decades of experience, focusing his practice on defending companies in patent infringement suits. His work spans a diverse range of technologies, including software, telecommunications, medical devices, automotive systems, and electronics. Based on his tracked representations, Mr. Heartfield exclusively defends accused infringers against patent assertions. All four of his appearances in the tracked case list are on behalf of the defendant, where he has served as both lead and local counsel.

Mr. Heartfield is the principal attorney at The Heartfield Law Firm in Beaumont, which he founded in 2006. The firm has a significant practice in the U.S. District Court for the Eastern District of Texas, where it has handled hundreds of cases. His representative matters include defending major corporations such as AT&T, Nissan, and Citigroup in patent cases. In Mimzi, LLC v. Nissan Motor Co., Ltd., court records indicate the case was concluded in early 2026 by a joint stipulation of dismissal, suggesting a settlement. His firm's public materials also note prior patent litigation work for clients including Microsoft, Verizon, and Boston Scientific.

Beyond district court litigation, Mr. Heartfield has experience in proceedings before the Patent Trial and Appeal Board (PTAB). He has represented clients in matters involving inter partes review (IPR) and has been a speaker at legal conferences on topics related to PTAB practice.

Mr. Heartfield earned his J.D. from the University of Tulsa College of Law in 1988 and a B.A. from Texas A&M University in 1985. He is a member of the State Bar of Texas and is admitted to practice in the U.S. District Courts for the Eastern and Southern Districts of Texas.