The rapid expansion of social media platforms has transformed the way consumers search for information, evaluate products, and make purchasing decisions. Social media influencers have emerged as powerful marketing agents whose credibility, authenticity, and online engagement significantly shape consumer attitudes and buying behavior. Despite their growing importance in digital marketing, there remains a need to better understand the extent to which influencer characteristics affect consumer purchase decisions across different demographic groups. Therefore, this study aims to examine the impact of social media influencers on consumer purchase decisions by investigating the roles of influencer credibility, trustworthiness, expertise, attractiveness, and audience engagement. A quantitative research design was employed using a structured questionnaire to collect primary data from active social media users through convenience sampling. The collected data were analyzed using descriptive statistics, correlation, and regression analysis to determine the relationships between influencer attributes and consumers' purchasing intentions. The findings reveal a significant positive relationship between social media influencer marketing and consumer purchase decisions. Trustworthiness, authenticity, and perceived expertise emerged as the strongest predictors of purchase intention, while interactive content and consistent engagement further strengthened consumer confidence in endorsed products. The study concludes that social media influencers play a vital role in shaping modern consumer behavior and enhancing brand effectiveness. These findings provide valuable implications for marketers, businesses, and digital advertising professionals seeking to develop more effective influencer marketing strategies, while also contributing to the growing body of knowledge on consumer behavior in the digital marketplace.