Over the last years, many aspects of people‘s lives have been moved to digitally supported environments. So far, the impact of these changes on their emotions and interpersonal processes remains largely unclear. As one essential and prevalent emotional process in social interaction, emotional contagion comprises the transmission of emotions between two or more individuals. In previous research, it has been studied in various interactive face-to-face contexts (e.g., teachers/students or psychotherapists/patients). In this study, we aimed to add to these findings by examining emotional contagion in dyadic online video conferences. We applied a lab-based experimental approach involving two participants interacting with each other via synchronized computers. In a structured interaction paradigm, they (N = 104 in n = 52 dyads) were prompted to talk to each other about recent personal experiences that made them angry, happy, and sad (in 3 conditions) while being filmed by webcams. The participants’ facial expressions during the interaction were analyzed using automated facial expression analysis software, and they retrospectively reported their subjective emotional experiences after each condition. Repeated measures analyses provided evidence of emotional contagion during the video conferences, as listeners reported to experience the speakers’ target emotions (anger, joy, sadness) significantly more frequently than any other emotion. We additionally employed cross-recurrence quantification analysis and found evidence for above chance co-occurrence of facially expressed anger and joy in both interaction partners. These findings point towards the existence of facial mimicry in online video conferences – a process that has been proposed as underlying mechanism of emotional contagion.