Sui Q. Duong, Counsel

Trademark attorney and former USPTO examining attorney with in-house experience

Sui leads Patterson + Sheridan’s trademark and brand protection group, focusing his practice on strategic prosecution and brand protection. He assists clients with clearance, counseling and obtaining trademark rights across a variety of industries. Thanks to his diverse experience operating in a variety of practice settings, Sui has the ability to develop creative, client-focused solutions that other attorneys might not consider.

Prior to joining the firm, Sui served as Director & Associate General Counsel at Western Digital Corporation. As the lead in-house trademark attorney, he managed a trademark portfolio spanning more than 140 countries with marks from the SanDisk, WD and HGST (formerly Hitachi GST) brands. In 2018, Brand Finance valued Western Digital and its family of brands at $7.5 billion USD.

Sui understands how decisions are made in the U.S. Patent and Trademark Office because he used to be an examining attorney himself. During his time at the USPTO, Sui reviewed over 3,000 classes of goods and services across all industries, and he also trained and mentored newly hired trademark attorneys at the USPTO headquarters in Alexandria, Virginia. He handled high-level review of prominent marks from major brands including Apple, Wal-Mart, Louis Vuitton and Kate Spade. 

As former Associate Counsel to then-Los Angeles Mayor Antonio Villaraigosa, Sui counseled members of the mayor’s staff on a variety of IP and ethical matters. He also led substantive commissioner deliberation meetings in service of the nation’s second-most populous city.

Sui received his law degree from UCLA and studied political science there as an undergraduate. He sits on INTA’s Trademark Office Practices Committee and has spoken at forums including LAIPLA’s Washington in the West Conference offering Strategies for Trademark Protection in Asia.

Sui is an active member of the Chinese American Citizens Alliance, one of the oldest Asian American civil rights organizations in the United States. He helped the nonprofit obtain a trademark registration for its name after 90 years of use. Sui is a Los Angeles sports fan, enjoys listening to a wide variety of music and can’t wait for the comeback of live concerts.

Practice Areas


  • J.D., University of California, Los Angeles School of Law, 2010
  • B.A., cum laude, University of California, Los Angeles, 2007

Bar Admissions

  • State Bar of California
  • United States Patent and Trademark Office

Professional Affiliations

  • International Trademark Association (INTA)
  • Orange County Asian American Bar Association