About Mark

Mark O'Donnell has built an extensive litigation practice around property and casualty insurance matters, including coverage disputes, bodily injury claims, and defence of brokers, real estate agents and other professionals accused of errors and omissions. He also defends institutions against sexual abuse claims and acts for domestic and foreign insurers in both insured claims and coverage disputes. He advises major insurers on multi-party toxic tort and environmental litigation and has coordinated the defence of several hazardous waste site claims. His work includes drafting legal opinions on insurance issues and assisting carriers with policy wording. Mark earned a Bachelor of Commerce with honours from McMaster University in 1979 and was later awarded a Bachelor of Laws by York University in 1982, after which he was called to the bar in 1984.

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This listing was generated by AI from public sources in August 2026. It may contain errors, and we can’t guarantee it’s accurate or complete. Before you rely on anything here, verify it on their firm’s website. Confirm Mark O'Donnell’s licence and standing in the Law Society of Ontario directory ↗

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