Background: While the relationship between speech, language and communication needs (SLCN) and mental health difficulties has been recognized, speech and language therapists (SLTs), and mental health professionals face challenges in assessing and treating children with these co-occurring needs. There exists a gap in the evidence base for best practice for professionals working with children and young people (CYP) who experience difficulties in both areas. Aims: To explore the views of SLTs and mental health clinicians about their experiences of working with CYP exhibiting co-occurring SLCN and mental health difficulties. Methods & Procedures: Semi-structured interviews were conducted with eight SLTs and six mental health professionals, including psychotherapists, clinical psychologists, play therapists and counsellors, with experience working with CYP with SLCN. Interviews were analysed using reflexive thematic analysis and themes were identified from the data. Outcomes & Results: Participants felt that SLCN and mental health difficulties frequently co-occur. Participants described how CYP with SLCN and mental health issues commonly experience difficulties across and between the domains of language and cognition, emotional well-being and challenging behaviour. Findings suggest that there are organizational limitations in the fields of SLT and mental health that have implications for the efficacy of assessment and treatment of CYP with SLCN and mental health difficulties. Traditional talking therapies were perceived to be inaccessible and ineffective for CYP with SLCN and mental health difficulties. Interventions blending behaviour and emotion programmes with language and communication interventions were considered potentially beneficial. Conclusions & Implications: Future research should explore and evaluate current services and service set-up in SLT and mental health. The findings from this study have important implications for the efficacy of treatments provided to this population suggesting that more research needs to be done into effective diagnosis and interventions for this population.