This study aimed to explore cases of young adult policy participation to ensure opportunities for participation across various young adult demographics and derive policy improvement strategies for enhancing young adult participation in Seoul. This research employed three main methods. Firstly, an analysis of the performance and limitations of Seoul's young adult participation policies was conducted through literature research and analysis of secondary data. Secondly, domestic and international case studies were conducted to examine the current status and examples of young adult participation systems both in Korea and abroad. Thirdly, an expert survey was conducted to diagnose the current state of young adult policy participation in Seoul and to derive strategies for enhancing young adult participation. Fourthly, focus group interviews (FGI) were conducted with participants and non-participants of Seoul's young adult participation policies. Finally, a policy symposium was organised to propose improvement suggestions for young adult participation systems in Seoul, presenting domestic and international cases and gathering opinions on proposed strategies. Based on results derived through these research methods, this study formulates a strategy and identifies challenges for activating young adult policy participation in Seoul.