Social interactions with weak ties (e.g., strangers, acquaintances) carry benefits for individuals and community. Beyond the quantity of weak-tie interactions, the emotional quality of these interactions may also be consequential. Positivity resonance occurs when two or more interacting individuals co-experience shared positive affect and caring synchrony. However, according to Positivity Resonance Theory, a precondition for the emergence of positivity resonance is perceived psychosocial safety. With greater economic inequality associated with threats to psychosocial safety, we hypothesize a breakdown in the positive emotional quality of weak-tie interactions, particularly for individuals with fewer resources. Using moderated-mediation analyses, two pre-registered studies found that when economic inequality was perceived as high, whether in prospective self-reports (Study 1; N = 1,044) or experimentally manipulated (Study 2; N = 903), income-based disparities emerged in the positive emotional quality of weak-tie interactions via markers of psychosocial safety. When economic inequality was perceived as low, income-based disparities are no longer present (Study 1). Additionally, randomization to high inequality (Study 2), versus low inequality, was associated with lower positive emotional quality of weak-tie interactions, regardless of income. These findings have implications for how rising economic inequality can erode the quality of day-to-day social encounters in communities, particularly for individuals with fewer resources. Barriers to high-quality social interactions may not only undermine community cohesion but may also exacerbate existing class-based health inequities.