This study aims to investigate the effectiveness of Social Media Influencers, Brand Image and Consumer Product Knowledge towards Purchase Intentions. A quantitative study was conducted on 200 millennial age TikTok users in Indonesia through an online survey using purposive sampling method. A regression analysis was carried out using IBM SPSS version 26 statistical software. The findings show that social media influencer, brand image and consumer product knowledge partially and simultaneously have significant effect on purchase intentions, with the largest contributing factor being consumer product knowledge. The adjusted R- square of this model is 0.604, signifying that the model was able to account for 60.4% of factors that affect purchase intentions. These findings aim to provide insight into marketing approaches on TikTok Indonesia.