This study is designed to suggest additional evidence-based reuse policy measures in Seoul by adopting two empirical methodologies: a material flow analysis and a questionnaire survey. The notion of a Circular City demands greater fundamental transition from recycling-focused policies towards systemic innovations which manifest source reduction and reused resource efficiency in a megacity such as Seoul. Despite its salient rationale, it is hard to find proper statistics and performance reports on the promotion of reuse policies in Seoul’s public policies, let alone in South Korea. In order to adopt more evidence-oriented reuse policies, this study aims to provide an overview of the landscape of reuse policies in Seoul by collecting information from two sources, resource organisations and citizens. A questionnaire survey reveals how Seoulites have (or have not) participated in reuse strategies and why (or why not) they plan to do so in the future. Material Flow Analysis (MFA) shows how three types of reuse actors such as charity shops, borough recycling centres, and throw-away-clothes-bins collectors have played major roles in this sector. Case studies on reuse centres and urban policies in Berlin and Helsinki add future possible policy solutions which can be introduced by the Seoul Metropolitan Government. The calculated contributions drawn from the MFA on resource reduction, climate change gas emission reduction, and employment maximization emphasise the importance of reuse policies in the future Seoul.