This study examines the relationship between social media use, disease risk perception, social and political trust, and out-group stereotyping and prejudice during a social upheaval. Analyses of primary data collected during the COVID-19 outbreak in Singapore found that disease risk perception is positively related to stereotyping and prejudice against Chinese immigrants. Individuals who used social media for news were more likely to stereotype and express prejudice. However, those who engaged in frequent heterogenous discussions, and had more extensive social networks, were less likely to stereotype and express prejudice. Higher social and political trust was also associated with lower stereotyping and prejudice. Finally, moderation effects of network characteristics on the relationship between risk perception, social trust, and prejudice were observed.