Young citizens increasingly turn to social media platforms for political information. These platforms enable direct communication between politicians and citizens, circumventing the influence of traditional news outlets. We still know little about the consequences of direct contact with politicians on such platforms for citizens’ political participation. Here, we argue that the interplay of different actors in the political news diet of citizens should be investigated from a networked communication perspective. Relying on a cross-sectional survey of young Danes (15–25 years old, n = 567), we investigate the relationship between following politicians on social media and: (a) the composition of young citizens’ political media diet; and (b) their civic messaging and campaign participation. Following political actors on social media relates to increased campaign engagement and can be a catalyst for young people’s exposure to campaign news, but their friends and followers function as the main node of their political online networks. We document a process of the de-mediation of politics on social media: Established news media lose influence as primary information sources for young citizens. We discuss these results in the context of users’ active curation and passive selection of their political social media diet.