More than one-third of American Millennial adults have obesity, and a significant amount of their household budget is spent on purchasing energy-dense and nutrient-poor food and beverage products. Consumers’ brand awareness and purchasing behaviors are influenced by celebrity credibility measured by trustworthiness, expertise and attractiveness; and celebrity ‘fit’ between products, brands and consumer’ self-image. This empirical mixed-methods study combined Q methodology with questionnaires to explore the shared and distinct viewpoints of demographically diverse Millennial adults about celebrity endorsement of food and beverage products or marketing campaigns in the United States (USA). Millennials (n = 40; aged 26–39 years) sorted photo images (n = 48) of US celebrities associated with branded food and beverage product endorsements on a 9-point normal distribution scale from ‘most trusted’ (+4) to ‘most distrusted’ (−4). Participants also completed a 4-item post Q-sort questionnaire to interpret their thoughts during the card sorting process, and a 3-item questionnaire to examine their views about celebrity credibility, ‘fit’ and multiple brand and product endorsements. Three distinct viewpoints were identified that included: (i) healthy lifestyle champions who trusted celebrities associated with healthy products or campaigns; (ii) female role-model admirers who trusted female celebrities associated with positive social impacts and (ii) African-American celebrity fans who trusted African-American celebrities who endorsed any brand or products. Qualitative analysis of the questionnaire identified the potential negative influence of celebrity endorsement for unhealthy products on Millennials’ dietary behaviors. Businesses and organizations should carefully select credible celebrities trusted by Millennials to encourage food and beverage products associated with a healthy diet.