The current study used a 2 × 2 analysis to explore the effect of athlete endorser-product congruence and endorser credibility on consumer responses, such as attitude toward the advertisement, attitude toward the brand, and purchase intention. Real people and actual brands were used as stimuli to enhance external validity and generalizability. Research results confirmed the interaction effects between athlete endorser-product congruence and endorser credibility on three specific consumer responses. The research further examined and identified the indirect path from attitude toward the advertisement and purchase intention, mediated by attitude toward the brand. The findings from the research fill gaps in the literature and extend the body of knowledge in endorsement studies in general and sport celebrity-endorsement studies in particular.