This study aims to investigate the impact of social media marketing activities (SMMAs) on purchase intention of skincare products among Indonesian young adults. The secondary objective of this study is to investigate the mediating effect of subjective norms, perceived behavioral control, brand awareness, and social brand engagement on the relationship between social media marketing activities on purchase intention of skincare products. Despite its popularity in the Indonesian market, the study on the impact of social media marketing activities on purchase intention of skincare products among Indonesian young adults has not been completely investigated and is still limited in Indonesia. This study adopts a quantitative crosssectional method. A total of 271 responses were collected from the respondents aged 18 to 34 years old through non-probability sampling. It was found that social media marketing activities (SMMAs) have a positive significant impact on purchase intention of skincare products among Indonesian young adults. Additionally, the relationship between social media marketing activities and purchase intention was significantly mediated by subjective norms, perceived behavioral control, brand awareness, and social brand engagement. The findings of this study will assist skincare brands’ marketers and future researchers to have useful insight into the impact of social media marketing activities on purchase intention of skincare products.