Calls have been made to rethink the mental health support currently available for young people. This study aims to help re-focus and reduce the inaccessibility of mental health services by offering an adapted version of a theoretically-driven, evidence-based, guided psychosocial intervention known as 'Groups 4 Health' (G4H). To date, the G4H intervention has mainly been trialled in Australia, with promising positive effects on social connection, mental health and well-being. The present study examines the feasibility of running a randomised controlled trial when delivering the G4H intervention for young people in the UK. The TOGETHER study is a feasibility randomised controlled trial of an adapted version of the G4H intervention. Participants are aged 16-25, currently experiencing mental health difficulties and recruited from mental health services. The target sample size is 30, with 15 in each trial arm. Participants are randomly allocated to either G4H plus treatment as usual, or treatment as usual alone. The primary outcomes of interest are the feasibility of recruitment, randomisation, data collection and retention to the study at 10 and 14 week follow up, as well as the acceptability, and accessibility of the study protocol and G4H intervention. The results of this study will indicate if further optimisation is required to improve the feasibility, acceptability and accessibility of the intervention and study protocol procedures as perceived by end users and practitioners. This offers a significant opportunity to support the local and national demand for accessible, innovative, and effective psychosocial youth mental health support.