About Mark

Mark Tonkovich is a partner in Toronto who co-leads the Tax Controversy and Litigation group. His practice focuses on resolving tax and tax-related public law disputes, representing major Canadian and international businesses in matters involving tax litigation risks, audits and negotiations with federal and provincial tax authorities. Tonkovich has appeared before the Tax Court of Canada, Federal Court, Federal Court of Appeal, Ontario Superior Court and the Supreme Court of Canada. Before joining the firm, he was a tax partner at another international law firm and a government tax litigator with the Department of Justice, and served as a judicial clerk at the Federal Court of Appeal.

Practice areas

Tax Law Civil Litigation & Dispute Resolution

Education & credentials

Law school
Osgoode

Listing compiled from public sources in August 2026. Confirm Mark Tonkovich’s licence and standing in the Law Society of Ontario directory ↗