This study explores the moderating effect of customers' Big Five personality traits on the relationship between influencer credibility and customer attitude towards promoted products/services. Data were collected from 245 participants in Egypt via a survey. Correlation and regression analyses were conducted using SPSS to test hypotheses and assess personality traits' impact on the influencer credibility-customer attitude relationship. Findings show that influencer credibility's influence on customer attitude varies across personality types. For extraverted individuals, attractive influencers have a positive influence, while trustworthy influencers have a negative effect. Open-minded individuals respond favorably to expert influencers but are less trusting of trustworthy ones. Agreeable individuals are more likely to be influenced by trustworthy influencers. However, conscientiousness and neuroticism do not significantly affect the influencer credibility-customer attitude relationship. These findings suggest other factors contribute to influencer marketing effectiveness. This study offers practical recommendations for influencers to impact their followers positively, considering personality traits, gender, and preferred platforms. Tailoring influencer campaigns to different personality types is crucial. By segmenting the target audience based on traits and creating resonant content, influencers can effectively engage with followers. For example, appealing to extraverts who respond well to attractive influencers can enhance campaign effectiveness. In conclusion, understanding and leveraging followers' personality traits, gender, and preferred platforms in influencer marketing is crucial. Tailored recommendations, audience segmentation and resonant content foster stronger relationships and influence attitudes. These insights guide influencers in optimizing strategies, cultivating meaningful connections, and ultimately enhancing the effectiveness of influencer-follower relationships in the dynamic landscape of social media.