While authenticity has been researched as a vital concept in various marketing streams, little is known in regard to consumer perceptions of authenticity in a CSR program and its effects on consumer responses. In particular, prior research on authenticity in CSR has not identified authenticity dimensions that are germane in the context of CSR in sport. The purpose of the current research is to (1) elucidate the key dimensions of CSR authenticity that are appropriate to the context of CSR in sport, (2) develop a valid and reliable instrument to measure authenticity in CSR activities in sport organizations, and (3) empirically test the effects of CSR authenticity on consumers’ behavioral intentions toward a sport organization. Following an in-depth review of literature on CSR and authenticity, five studies were conducted to (1) validate proposed dimensions of CSR authenticity (community link, reliability, commitment, congruence, benevolence, transparency, and broad impact), (2) develop a CSR Authenticity Scale including a qualitative approach (five focus group interviews; Study 1) as well as a quantitative approach (Studies 2 and 3), and (3) ultimately show the effects of CSR authenticity on consumers’ behavioral intentions toward a sport organization (Studies 4 and 5). Across five studies, the current research introduces a reliable and valid multidimensional CSR Authenticity Scale and empirically shows the significant effects of CSR Authenticity on consumer behavioral intentions toward an organization and its CSR campaign across two different sports. CSR Authenticity particularly had a great deal of influence relative to consumers’ responses about consumers’ feelings about the organization and its CSR campaign. The current research fills the knowledge gap and broadens our understanding of CSR Authenticity as a multidimensional construct by developing a psychometrically robust measure of CSR Authenticity. To the author’s knowledge, this is the first research that presents a multidimensional measure of CSR Authenticity. The current research also fills the knowledge gap by adding empirical evidence of the effectiveness of CSR Authenticity on various consumer-outcome variables. Lastly, this research may help organizations when they initiate, design, implement, and revise their CSR programs so that they can maximize their long-running benefit to society.