This paper applies moral foundations theory in the context of consumer ethics. The purpose of the study is to examine whether moral foundations theory can be utilised as a theoretical framework to explain consumers’ beliefs regarding both ethical and unethical consumption. The relationships among various moral foundations and different dimensions of consumer ethics are examined with a sample of 450 US consumers. The results demonstrate that, among the various moral foundations, only the sanctity/degradation foundation is negatively related to beliefs regarding all forms of unethical consumer actions (actively benefiting from illegal actions, passively benefiting from the mistakes of the seller and actively benefiting from legal but questionable actions) as well as ‘no harm, no foul’ actions. On the contrary, the care/harm, fairness/cheating and authority/subversion foundations are related to positive beliefs regarding ‘doing good’ actions. This indicates that moral motivations for supporting pro-social actions as a consumer are not necessarily the same as moral motivations for condemning unethical actions. The findings also demonstrate that the loyalty/betrayal foundation is positively related to beliefs regarding unethical consumer actions and negatively related to perceptions of pro-social consumer actions. This demonstrates that in-group loyalty leads to supporting unethical actions. Furthermore, the results show that various moral foundations mediate the relationships of idealism with consumers’ ethical beliefs. Hence, various moral foundations can explain the effects of personal variables on consumer ethics.