Abstract: This paper examines the health-related quality of life (HRQL) and mental health of adolescent young carers (AYCs) aged 15–17 in Switzerland, based on data collected within the Horizon 2020 project ‘Psychosocial support for promoting mental health and well-being among AYCs in Europe’ (ME-WE). It addresses the following questions: (1) Which characteristics of AYCs are associated with lower HRQL and with higher level of mental health problems? (2) Do AYCs who are less visible and less supported report a lower HRQL and more mental health issues than other AYCs? A total of 2343 young people in Switzerland, amongst them 240 AYCs, completed an online survey. The results show that female AYCs and AYCs with Swiss nationality more often reported having mental health issues than their male and non-Swiss counterparts. Furthermore, the findings show a significant association between receiving support for themselves and visibility from their school or employer and the HRQL. Moreover, AYCs who reported that their school or employer knew about the situation also reported fewer mental health issues. These findings can inform recommendations for policy and practice to develop measures aimed at raising the visibility of AYCs, which is the first step for planning AYC tailored support.