There were 300 million selfies posted on Instagram in 2018 (Smith 2019), and many people are taking selfies with brands (Sung et al. 2018). Although brand selfies of average consumers are generally perceived as credible, some consumers generate fake brand selfie pictures. Furthermore, viewers evaluate credibility of a brand selfie based on its composition, as well as its components such as brand, person and context. Even though marketers need to choose reasonably credible brand selfies to use for their promotions, little is known about how viewers assess the credibility of a brand selfie. Hence, this research aims to develop a scale to empirically measure brand selfie credibility from the viewer’s perspective, and to identify the antecedents and outcomes of brand selfie credibility. The scale development followed established scale development methods (e.g., Churchill 1979). Based on exploratory qualitative and quantitative studies, this research project developed a 9-item scale to measure brand selfie credibility. Three dimensions identified through an exploratory qualitative study and confirmed by two expert panels are: brand selfie image trustworthiness, brand selfie congruence, and brand selfie meaning. This research also finds that brand selfie credibility is influenced by brand-related, person-related, and image-related antecedents. Additionally, brand selfie credibility impacts on purchase intention and positive word-of-mouth. This study provides a tool for marketers to understand consumers’ perception of brand selfies and consumers’ reactions. Marketers can identify how the brand selfie and its credibility can be leveraged for marketing purposes. This is the first study to develop and validate the measures for brand selfie credibility on social media which contributes to user-generated content, influencer-generated content, photographic credibility and branding literature.