The COVID-19 pandemic contributed to longer waiting lists for people seeking to access mental health services. The NHS Five Year Forward View encourages the development of empowerment-based social prescribing interventions to supplement existing mental health programmes. Based in South Wales, EmotionMind Dynamic (EMD) is a lifestyle coaching programme that supports individuals suffering from anxiety or depression. In this evaluation of lifestyle coaching, a mixed-method social return on investment (SROI) methodology was used to value quantitative and qualitative data from face-to-face and online participants. Data collection took place between June 2021 and January 2022. Participants included both self-referred clients and those referred from health services. Mental wellbeing data were collected at baseline and at the end of the programme using the short Warwick–Edinburgh Mental Wellbeing Scale (SWEMWBS) and the General Self-Efficacy Scale (GSES). Baseline and follow-up data were available for 15 face-to-face participants and 17 online clients. Wellbeing valuation quantified and valued outcomes from participants. Results indicated that for every GBP 1 invested, lifestyle coaching generated social values ranging from GBP 4.12–GBP 7.08 for face-to-face clients compared with GBP 2.37–GBP 3.35 for online participants. Overall, lifestyle coaching generated positive social value ratios for both face-to-face and online clients.