This article focuses on a neglected aspect of the climate action movement Fridays for Future, namely, the relationship between its mediated communication practices and its early organizational processes. Drawing from a strand of organizational communication that underscores the constitutive dimension of communication to organizing processes, we analyze the significance of mediatized leadership and networked communication for the foundation and early development of two national chapters of Fridays for Future: Youth for Climate (YFC) Belgium and Fridays for Future Italy (FFFI).