William T. Ellis

Retired Partner


William T. Ellis is a partner and intellectual property lawyer with Foley & Lardner LLP. His practice focuses on the representation of emerging and mainline technology companies. Mr. Ellis is a member of the firm’s Electronics and International Practices.

He serves his clients as counsel in matters of intellectual property litigation, patent infringement and validity opinions; patent procurement in business method, e-commerce, software, telecommunication, semiconductor, electronic and mechanical technologies; and licensing of patents, trade secrets and trademarks.

Mr. Ellis has set up patent positions for:

  • software companies
  • hardware companies
  • banking groups
  • e-commerce companies
  • consumer products companies

Mr. Ellis has over 25 years of industry experience in intellectual property counsel. He was formerly Intellectual Property counsel at IBM where he held the dual role of IP counsel for the IBM global network telecommunication company and for several software companies wholly owned by IBM. Mr. Ellis also served as IBM managing counsel in the areas of computer systems, semi-conductor chips, and circuitry and negotiated numerous patent licenses for IBM.

Before joining IBM, Mr. Ellis was chief IP counsel at the Naval Research Laboratory, working in the areas of electronic circuitry, semiconductor devices, optical communications, new materials and coatings. He is a former USPTO patent examiner in the area of modulated carrier systems, radio and television.

Thought Leadership

Mr. Ellis has been called as an expert witness on patent law in numerous patent litigations in the federal courts. He was principal author for the amicus brief filed by the Information Technology Industry Council on software patentability in the State Street Bank appeal before the Federal Circuit Court of Appeals. Mr. Ellis has also been a frequent author and lecturer on intellectual property issues in the U.S. and abroad.


In recognition of his experience, Mr. Ellis has also been Peer Review Rated as AV® Preeminent™, the highest performance rating in Martindale-Hubbell's peer review rating system.


As a member of the American Bar Association, Mr. Ellis has chaired the Computer Programs and Information Retrieval Committees and ABA Division 7-Information. He was also a member of the Industry Functional Advisory Committee on Intellectual Property Rights for Trade Policy Matters (IFAC-3) and has served as Information Technology Industry Council Delegate, Committee of Experts Session, Berne Protocol in Geneva.


Mr. Ellis graduated from the University of Illinois (B.S., electrical engineering), where he was named an Edmund James Scholar, and from Catholic University, Columbus School of Law (J.D.).


Mr. Ellis is admitted to practice in the District of Columbia, New York and Virginia, and before the U.S. Patent and Trademark Office, the U.S. Court of Claims, and the U.S. Court of Appeals for the Federal Circuit.

Publications and Presentations

  • Patenting Business Methods in the Financial Services Industry Conference, Chair, New York, NY (2004-2007)
  • "Protecting your Technology: The Use of Intellectual Property," Inside the Minds: The Laws Behind Technology (Aspatore, Inc., 2004)
  • "The Chip Protection Act," Intellectual Property Counseling and Litigation (Matthew Bender, 1988)
  • "Patent Asset Strategy and Management," Pacific Intellectual Property Assoc., Dearborn, MI (2003)
  • "Open Source Software Licensing," Pacific Intellectual Property Assoc., Fukuoka, JP (2002)
  • "Strategy for Patenting Internet Business Methods and Other Inventions in the 21st Century and Litigation Related Issues," Pacific Intellectual Property Assoc., Boston, MA (2001)
  • "Federal Criminal Trade Secret Law; The Economic Espionage Act," IPO (1997)
  • "Software Invention Patentability and the State Street Bank Case," IPO (1996)
  • "The Role of Patents in the Development of the Software Industry," Conference of the Americas, Los Angeles (1996)
  • "Intellectual Property Rights in the Framework of the Joint EU-US Action Plan," Rome, Italy (1996)
  • "Patent and Copyright Protection for Software in the Post TRIPs World," Council on Foreign Relations (1996)
  • "The Global Treatment of Statutory Subject Matter in the Year 2000," AIPLA (1996)
  • "New World of Software Patents," ABA (1995)
  • "North American Free Trade Agreement," Pacific Intellectual Property Association (1993) 
  • "Standards and Intellectual Property," Harvard NIST (1994)
  • "Copyright Protection for Computer Programs," International Copyright Institute (1993)
  • "Software Protection in Eastern Europe and the USSR" and "Copyright Protection for Computer Software," Prentice-Hall Law and Business (1990)