Online marketplaces matching third-party sellers with consumers are now key e-commerce channels globally. Despite their popularity and the benefits they bring to consumers, they do present a number of risks, for example when their third-party sellers engage in misleading marketing and fraud, or supply unsafe products. This report summarises results from a 2021 OECD survey of 28 countries and 15 platform businesses examining the role of online marketplaces in enhancing consumer protection. The report highlights a range of encouraging initiatives by many participating countries and online marketplaces to better protect consumers, often taken in co-operation with one another, but also identifies several key areas where more action is needed.