The aim of the present study was to test the classic but under-researched hypothesis that individual differences in automatic emotional mimicry are positively related to individual differences in emotional contagion. To tap automatic mimicry and automatic emotional contagion, participants were exposed to affective stimuli with either a positive or negative valence (faces with a happy expression, n = 73; faces with a sad expression, n = 73) while their attention was directed toward nonaffective features of the stimuli. Emotional mimicry was measured with EMG (Corrugator, Zygomaticus). On average, in the sad emotional expression condition, participants’ mood worsened, but the happy emotional expression condition did not evoke a general positive emotional contagion effect (across participants). Multigroup multilevel latent difference models revealed that in the sad emotional expression condition, individual differences in Corrugator activity were related to a larger increase in unpleasant mood, and in the happy emotional expression condition, individual differences in Zygomaticus activity were related to a larger decrease in unpleasant mood. That is, results of this study provided support for the mimicry-contagion link.