This article introduces the concept of sustainability‐rooted anticonsumption (SRAC), which refers to consumers' anticonsumption practices of voluntary simplicity in living and, on a smaller level, collaborative consumption and boycotting with the goal of supporting sustainable economic development. The SRAC measurement approach is validated based on three empirical studies. Results of a representative German sample (Study 2) reveal that SRAC is predominantly negatively linked to consumer overconsumption dispositions. Exemplary, voluntary simplification and boycott intention may result in declining levels of indebtedness. Study 3 shows that psychosocial well‐being is positively related to SRAC and overconsumption. However, a simplified lifestyle and a greater willingness to boycott are not necessarily associated with psychosocial well‐being. This article provides insights for practitioners and policymakers to leverage existing SRAC values via “new” business models (sharing offers) or to influence the existing level of consciousness to effectively pave the way for solid progress in the sustainability movement.