Social marketing has been established with the purpose of effecting change or maintaining people’s behaviour for the welfare of individuals and society (Kotler and Zaltman in J Market 35:3–12, 1971; MacFadyen et al. in The marketing book, Butterworth Heinemann, Oxford, 2003; French et al. in Social marketing and public health: Theory and practice, Oxford University Press, Oxford, UK, 2010), which is also what differentiates it from other types of marketing. However, social marketing scholars have struggled with guiding social marketers in conceptualising the social good and with defining who decides what is socially beneficial in different contexts. In this paper, we suggest that many dilemmas in identifying the social good in social marketing could be addressed by turning to human rights principles, and, in particular, by following a human rights-based approach. We examine a number of cross-cutting human rights principles—namely, transparency and accountability, equality and non-discrimination, and participation and inclusion—that are capable, in a practical way, of guiding the work of social marketers. Through an illustrative case study of the anti-obesity discourse, we present how these principles might help to address some of the challenges facing social marketing, both as a theory and practice, in meeting its definitional characteristic.