Contemporary television series, above all those of Teen TV, often present tragic processes of isolation that regularly escalate in a catastrophic finale of total social isolation. For example, the controversial series 13 Reasons Why (USA 2017–2020, Netflix), about the suicide of a high school student, essentially tells of agonizing social alienation from which its characters suffer. Yet these telemedial lonelinesses do not only play out on a narrative level: It is the aesthetic interplay of character drawing, props and the connected discourses with the specific staging forms, spaces and sound worlds of television which is producing strong modes of expression for the otherwise often invisible, difficult-to-name and abstract processes of late-modern loneliness to which young people in particular are exposed in contemporary Western post-industrial societies. In doing so, television refers to an iconography of modern loneliness already firmly established in the history of art and film and, through its inherent aesthetic layers, escalates in the complex structure of telemedial forms of expression. Against the background of a brief socio-philosophical history of modernity as an epoch of increasing loneliness, an exemplary analysis of the series 13 Reasons Why will be used to make suggestions as to how these telemedial aesthetics of loneliness can be described and thought together more precisely.