Olivier Nguyen's practice covers all aspects of civil and commercial litigation, including corporate disputes, government procurement and commercial contracts, banking affairs, class actions and civil liability. He acts for clients before the courts of Quebec and Ontario, the federal courts, the Canadian International Trade Tribunal and regulatory authorities.

Mr. Nguyen also practises in international trade law. He handles import and export commercial matters, anti-dumping actions, free-trade agreements and economic sanctions.

In regard to government procurement, Mr. Nguyen advises public and private clients throughout Canada on complex issues relating to calls for tenders and government contracts, including in particular preparing and drafting calls for tenders and handling government procurement disputes.

Since 2013, Mr. Nguyen has been supervising the activities associated with University of Ottawa's involvement in the Charles-Rousseau Moot Court Competition in International Law, and in 2015, he taught the common law course on property law.