Research on the association between social anxiety and social media usage remains inconclusive: despite the preference for computer-mediated communication there is currently no clear empirical support for social anxiety being associated with longer duration of social media use. Self-report measures for social anxiety that are adapted for the context of social media could facilitate further research. The current study aimed to develop a Swedish version of the recently developed Social Anxiety Scale for Social Media Users (SAS-SMU), evaluate its psychometric properties, and explore associations between different uses of social media and social anxiety. Three factors were retained for SAS-SMU with excellent internal consistency. SAS-SMU evidenced convergent validity with measures of social anxiety, negative convergent validity with satisfaction with life, and divergent validity with measures of obsessive-compulsive disorder, depression and generalized anxiety disorder. Results indicated that higher levels of social anxiety were associated with passive and active use as well as longer duration of social media use in general, which is at odds with a previous study where passive use remained the only significant predictor for social anxiety.