This Practice Note seeks to assist businesses with complex international supply chains to adopt and implement consistent practices on child labor. It provides guidance on the definition of child labor under international law and how this intersects with applicable domestic law, before considering the responsibility of purchaser companies to respect children’s rights. The Note also provides an overview of the Fighting Against Forced Labour and Child Labour in Supply Chains Act (a new Canadian law which bans the import of goods made with child labor), as well as child labor law in the US and the UK. Complying with laws on child labor is integral to wider corporate environmental, social and governance (ESG) and sustainability strategy.