There is a need for brief, accurate screening scales for social anxiety disorder to enable better identification of the disorder in research and clinical settings. A five-item social anxiety screener, the Social Phobia Screener (SOPHS), was developed to address this need. The screener was validated in two samples: (a) 12,292 Australian young adults screened for a clinical trial, including 1,687 participants who completed a phone-based clinical interview and (b) 4,214 population-based Australian adults recruited online. The SOPHS (78% sensitivity, 72% specificity) was found to have comparable screening performance to the Social Phobia Inventory (77% sensitivity, 71% specificity) and Mini-Social Phobia Inventory (74% sensitivity, 73% specificity) relative to clinical criteria in the trial sample. In the population-based sample, the SOPHS was also accurate (95% sensitivity, 73% specificity) in identifying Diagnostic and Statistical Manual of Mental Disorders–Fifth edition social anxiety disorder. The SOPHS is a valid and reliable screener for social anxiety that is freely available for use in research and clinical settings.