The use of celebrity endorsement as an advertising strategy has been widely embraced by numerous organisations. Nonetheless, scholarly wisdom suggests the need for cumulative research that seeks to identify the unique set of source factors that enhance the credibility of advertising communication messages delivered by celebrities across countries. In this vein, the primary purpose of this research was to apply the dimensions of the source attributes theory (Ohanian, 1990) to understand the underlying factors that influence South African consumers to have positive perceptions towards purchasing a product that has been endorsed by a local athlete celebrity-endorser. A quantitative research approach was applied, wherein a self-administered survey questionnaire comprising 20 scale items was adapted for this research. Data were collected from a consumer sample of 456 consumers based in Gauteng, South Africa. Upon applying exploratory factor analysis and mean score rankings, source likeability, source trust, source authority and source credibility were established as the underlying factors influencing consumers’ credibility evaluations, in descending order of importance. Moreover, the inter-factor correlation matrix revealed positive relationships among the identified factors. Insights gained from this study could assist practitioners to design effective advertisement strategies that foster positive credibility evaluations through known product endorsers.