Professional Biography
Image of Evan Day

Evan S. Day Senior Counsel

  • San Diego

    D +1.858.720.5700

    F +1.858.720.5799

    San Diego

    11452 El Camino Real, Suite 300

    San Diego, CA 92130-2080




Evan Day is an experienced patent litigator with a history of securing wins for clients in a variety of forums, including jury and bench trials. Evan practices in the areas of patent litigation, U.S. International Trade Commission Section 337 investigations, post-grant procedures, including inter partes review (IPR) trials before the USPTO Patent Trial and Appeal Board (PTAB) and due diligence investigations. He has represented clients in litigation matters spanning a wide variety of technologies, including light-emitting diodes (LEDs), control systems, optics, displays, user interfaces, mapping services, navigation systems, audio applications, image processing, home audio/visual networking (including UPnP and DLNA), Internet of Things, touch-sensitive interfaces, digital graphics, electronic gaming systems, DNA testing, and virtual and augmented reality.

As part of Evan’s extensive PTAB experience, he has litigated several IPR cases through oral hearing and final written decisions decided in favor of firm clients, and participated in drafting numerous petitions for IPR which resulted in institution decisions and favorable settlements.

A former judge advocate in the U.S. Marine Corps, Evan served primarily as a prosecutor while on active duty. He tried complex felony-level, court-martial cases, before both judges and juries, involving such offenses as rape, obstruction of justice, conspiracy, larceny, fraud and narcotics manufacturing and distribution. Evan continues to serve as an attorney in the Marine Corps Reserve with the rank of Major.

Fewer Bites at the IPR Apple? Impact of Recent Decisions and Guidance on Multiple Petitions thumbnail

Fewer Bites at the IPR Apple? Impact of Recent Decisions and Guidance on Multiple Petitions

What can you expect when multiple inter partes review petitions are filed against the same patent?

Click here for the full publication.

Professional Recognition

  • Listed as a "Top Forty Under Forty" by Daily Transcript, 2020
  • Awarded American Bar Association "Award for Professional Merit" for graduating first in class at the Naval Justice School in Newport, RI, 2009

Related Employment

  • U.S. Marine Corps, Judge Advocate, 2008 - 2011
  • Henry M. Jackson Foundation for the Advancement of Military Medicine, Rockville, MD, Intellectual Property Paralegal, 2007 - 2008
  • Hamilton, Brook, Smith and Reynolds, P.C., Concord, MA, Summer Associate, 2006





Bar and Court Admissions

  • California
  • U.S. Patent and Trademark Office
  • U.S. District Court for the Southern District of California
  • U.S. Court of Appeals for the Federal Circuit


  • Georgetown University Law Center, J.D., 2007
  • Harvard University, B.A., Biology, cum laude, 2003


Bio In Other Languages

Simplified Chinese Bio | 中文简体