Social media has become an integral part of our daily lives. Influencers have emerged as significant players in promoting sustainable consumption in recent years. With their reach and influence, they have the ability to sway consumer decisions and earn rewards from marketers. However, an influencer’s perceived importance and credibility among their followers is essential to their ability to persuade others. In this study, we utilized network theory and the theory of mind to scrutinize the impact of an influencer’s importance and credibility on sustainable consumption. We collected data from 427 consumers and conducted structural equation modeling (SEM) to test our hypotheses. Our findings indicate that an influencer’s importance has a positive impact on their credibility, which subsequently has a favorable impact on cognitive, affective, and conative sustainable consumption. These results confirm the importance and credibility of influencers in promoting sustainable consumption and provide insights into how social marketers and influencers can optimize their sustainable marketing strategies.