The development of e-commerce has complicated the decision-making process. Emphasizing conscious decision-making has yielded inconsistent results for sustainable consumption, often overlooking the unconscious influences. This study used digital nudges to enhance sustainable fashion consumption (SFC) among Gen Z consumers in southeastern Europe, whose environmental awareness does not always translate into buying habits. Recognizing Gen Z’s emphasis on togetherness and sustainability, the study focused on social influence and the environmental performance of fashion products. One hundred participants (41 males, 58 females, and 1 non-disclosed) were divided into two groups and completed six online questionnaires on purchase intention, willingness-to-pay, green trust, green perceived value, and word-of-mouth for six fashion product categories. The six MANOVAs confirmed that participants exposed to social norm nudges (experimental group) in fictitious e-commerce settings scored higher on all dependent variables. The results suggest that social nudges are a cost-efficient, promising tool for fashion retailers, providing a holistic understanding of products’ environmental and social values for Gen Z.