Youth political participation is increasingly recognized as a critical driver of sustainable governance and social transformation. This study aimed to examine the impact of youth political participation on sustainable development outcomes in Bangkok, Thailand, with a particular focus on SDG 16 (peace, justice, and strong institutions) and SDG 11 (sustainable cities and communities). A quantitative explanatory design was employed, using multi-stage sampling to collect 372 valid responses from youth aged 18–30 years. Data were analyzed through descriptive statistics, correlation, and multiple regresssion analysis using Jamovi 2.3.28. The results revealed that all five dimensions, political awareness, civic engagement, digital political participation, institutional trust, and perceived political efficacy, significantly predicted sustainable development outcomes, explaining 52% of the variance. Perceived political efficacy was the strongest predictor. The findings highlight the importance of empowering youth, promoting political literacy, and leveraging digital participation to advance the Sustainable Development Goals