Katherine H. Tellez

Katherine H. Tellez is a patent litigation partner at Steptoe, known for her expertise in high-stakes patent infringement matters. Her practice encompasses a broad range of technical fields, including software-based inventions, pharmaceuticals, consumer goods, automotive parts, medical devices, computer networking, and fiber optic equipment. She has a demonstrated history of representing patent owners, as evidenced by her significant plaintiff-side victories and her published work on patent monetization strategies. Tellez rejoined Steptoe in October 2025, bringing more than a decade of experience and prior tenure with the firm, as well as experience from a litigation finance provider.

Tellez has secured notable outcomes for her clients, including a $170 million jury verdict for Express Mobile, Inc. against GoDaddy.com, LLC for willful infringement of foundational web-design patents. This verdict followed a successful appeal to the US Court of Appeals for the Federal Circuit. In a related "first-of-its-kind" decision, the Patent Trial and Appeal Board (PTAB) later relied on the jury's non-invalidity finding to rule in Express Mobile's favor in parallel inter partes review (IPR) proceedings. Other significant results include a $40 million jury verdict for Express Mobile against Shopify related to mobile phone and website functionality, a multi-million-dollar jury verdict in a software patent trial, and a trial win in an automotive patent dispute. She also achieved the reversal of a $39 million damages award in a pharmaceutical patent suit after successfully invalidating the patent on appeal for Sandoz.

Her practice extends to PTAB and International Trade Commission (ITC) proceedings. Tellez has experience in IPRs, including securing a rare Federal Circuit reversal of an IPR determination of no anticipation. Her strategic and decisive approach has led to prevailing on behalf of clients in federal district courts, USPTO proceedings, appeals before the Federal Circuit, and ITC investigations.

Katherine H. Tellez earned her J.D., cum laude, from the University of Illinois College of Law in 2010 and holds a B.S. in Chemical Engineering from the University of Illinois Urbana-Champaign (2007). She is admitted to practice in Illinois, before the US Patent and Trademark Office, the US Court of Appeals for the Federal Circuit, and the Supreme Court of the United States.