The importance of ethical behavior in consumers has never been so evident, and in recent years, researchers have generated a great deal of knowledge about ethical consumption. The search for happiness in consumption has been a recurrent line of research by academics of the management and, mainly, the marketing fields. Our study analyses the relationship between ethical and sustainable behavior in consumption and the achievement of consumer happiness. Employing structural equations, the findings of the study suggest that there is a positive relationship between consumers’ predisposition toward sustainable behavior and happiness. In addition, the findings indicate that, when there are reasons to justify unethical behavior in consumption, the consumer also manages to be happier. Important implications for theory and practice are derived from the results. Emphasizing the benefits of sustainable consumption for enhancing happiness might instigate sustainable consumption, especially in the case of those consumers who do not have a positive attitude toward sustainable consumption.