Single session therapy (SST) is grounded in the belief that clients and families can effect change after one therapeutic encounter, using their own resources, with brief support and assistance from therapists. SST has been found to be an effective intervention for children, young people, and their families presenting with a wide range of difficulties. Research in child and adolescent mental health has shown that over 50% of families find one SST encounter is enough with no need for further specialist input. This study aims to explore family member experiences of SST (undertaken as single session family therapy and termed hereafter SSFT) as an initial intervention in a regional child and adolescent mental health service (CAMHS), specifically in terms of worry, confidence, and satisfaction outcomes. An exploratory, mixed methods convergent design was utilised using a combination of open questions and Thurstone scales. All eligible family members were invited to complete questionnaires before and after the SSFT, asking about level of worry, confidence, and overall satisfaction with SSFT. Quantitative and qualitative findings indicated most family members had a positive experience of SSFT, although differences were found between young people, parents, and siblings. Overall, family members’ level of worry decreased, while only parental confidence in managing the presenting issue(s) increased. Over half of the families did not require further contact with CAMHS following the SSFT. Our findings support previous research that SSFT is an effective, family‐inclusive, and well received intervention for a variety of mental health issues facing children and young people. SSFT could be considered a beneficial and well received first response for the majority of CAMHS clients, which prioritises a family‐inclusive approach. Future research could focus on attaining a more in‐depth understanding of individual family member experiences with a view to improving SST delivery.