The term sustainable consumer (SC) behaviour is recognised as the extent to which consumption decisions are made with the goal of minimising or improving the effects on society and the environment. The global market is often thought to be socially and environmentally aware of how humans affect the environment. However, responses and expectations of consumers may vary depending on contextual variables of their region. For example, while individuals at the BoP markets in emerging economies are concerned about the environment, questions regarding prices and personal benefits may override when making purchase decisions. In this chapter we discuss the dimensions and complexities of sustainable consumer (SC) behaviour including segmentation characteristics, SC predictors and willingness to pay with a special focus on consumers in emerging markets that are largely operating at the BoP. Thereafter, we propose a comprehensive description of a SC by bifurcating pertinent and relevant factors that are known to be helpful in predicting SC behaviour among internal or external influences on the individual (actor) or behaviour (actions). At the end, we elucidate few recommendations for practitioners and policymakers. The description of a SC will be useful to environment and social marketers who wish to target consumers and design intervention strategies for this target group, and researchers who wish to expand SC studies.