Desmond P. O'Sullivan

Of Counsel | San Diego | (858) 314-7794
(858) 314-7794

Desmond O’Sullivan assists clients in procuring patents before the U.S. Patent and Trademark Office (PTO), litigating patents before U.S. district courts, defending and attacking patents before the Patent Trial and Appeals Board, and evaluating patents and other intellectual property in corporate transactions. Desmond’s experience in various intellectual property disciplines brings additional value to his clients.

Desmond’s patent procurement practice includes the preparation and prosecution of patent applications for multinational, domestic, and startup companies. Desmond’s prosecution practice has covered methods and systems directed to agtech, artificial intelligence, natural language processing, algorithms for data management, neural networks for security, medical devices, telecommunications, alternative energy, aviation, engines, and consumer electronics.

Desmond’s patent litigation practice includes representing multinational and U.S.-based companies in litigation and arbitration matters. Desmond has created offensive and defensive strategies for intellectual property related to antennas, telecommunications, laser systems, semiconductors, codecs, and medical devices.

Using his litigation and prosecution experience, Desmond regularly participates in adversarial proceedings at the PTO. Desmond has represented patent owners and patent challengers in inter partes reviews, ex parte reexaminations, and interferences. He regularly counsels clients when choosing adversarial proceedings in the PTO to complement co-pending litigation strategies.

Desmond is a member of the San Diego Intellectual Property Lawyers Association, and currently serves as its President.

Desmond received his J.D. from Hastings College of the Law, where he was an articles editor for the Hastings Law Journal and served as a judicial extern for the Honorable Vaughn R. Walker of the Northern District of California. As an extern to Chief Judge Walker, Desmond assisted the court with patent claim construction and in fulfilling duties as a designated member of the United States Court of Appeals for the Federal Circuit.

Desmond received his B.Sc. in mathematics and applied mathematics from University College Cork in Cork, Ireland. He received his M.S.E. in engineering sciences from the University of California, San Diego, where he focused on aerospace and mechanical engineering.

Show More


Unsolicited e-mails and information sent to Morrison & Foerster will not be considered confidential, may be disclosed to others pursuant to our Privacy Policy, may not receive a response, and do not create an attorney-client relationship with Morrison & Foerster. If you are not already a client of Morrison & Foerster, do not include any confidential information in this message. Also, please note that our attorneys do not seek to practice law in any jurisdiction in which they are not properly authorized to do so.