Bill Mayo

Bill Mayo



20 Queen Street West
Suite 3300
Toronto, ON
M5H 3R3

Bill is partner in Aitken Klee’s Toronto office. His practice involves all aspects of intellectual property law, including strategic advice, litigation, including trademark oppositions, providing clearance and validity opinions, and trademark and patent prosecution. Bill has extensive experience advising pharmaceutical companies with respect to IP and regulatory issues, including with respect to the Patented Medicines (Notice of Compliance) Regulations.

A registered Canadian Patent and Trade-mark agent, Bill sits on the executive of AIPPI Canada and is a regular speaker on intellectual property issues. He is recognized as a leader in intellectual property in the 2016 edition of Chambers Global: The World’s Leading Lawyers for Business, and as one of the best Canadian patent lawyers by Who’s Who Legal and the 2016 edition of The Best Lawyers in Canada (Woodward/White). Bill is also recognized by Martindale Hubbell and is included in Intellectual Management’s IAM Patent 1000 – The World’s Leading Patent Practitioners (2016) and in the current Canadian Legal Lexpert Directory.  

Bill has been involved in a number of important intellectual property litigation cases. In 2007, Bill, along with his colleague Jon Stainsby, received international recognition from Managing Intellectual Property magazine for their work on Sanofi-Aventis Inc. v. Novopharm Ltd., 2007 FCA 163, the Canadian IP Case of the Year.

Prior to joining Aitken Klee in 2014, Bill practiced intellectual property law with firms in Toronto and Ottawa and as in-house IP counsel at Newbridge Networks.


LL.B., University of British Columbia, 1990
M.Sc., Queen’s University, 1988
B.Sc., Queen’s University, 1986

Professional Affiliations

Canadian Bar Association
Intellectual Property Institute of Canada
International Association for the Protection of Intellectual Property
The Law Society of Upper Canada (Ontario)