Mark David Franklin Sheeley

Mark has a wide-ranging corporate-commercial litigation practice, with expertise in complex contractual disputes, class actions, tax litigation, complex financial matters, and insolvencies.

Mark is committed to client service, identifying and obtaining practical results that meet his clients’ objectives, whether in the courtroom or the boardroom. He is a co-leader of Osler’s case assessment team, which specializes in analyzing and valuing complex disputes. He has appeared before courts across Canada, including the Ontario Superior Court of Justice (Commercial List), Court of Appeal for Ontario, Tax Court of Canada, Federal Court of Appeal and Supreme Court of Canada.

On February 18, 2021, the Supreme Court of Canada declined the Crown’s application seeking leave to appeal the June 2020 decision of the Federal...

The Federal Court of Appeal upheld the Tax Court’s decision that Cameco’s transactions with its Swiss subsidiary were on arm’s length terms...