Objective: Given the potential benefits of digital mental health (DMH) interventions, especially post-COVID-19, ample research focuses on factors that prevent mental health professionals (MHPs) and consumer engagement with DMH technologies. However, questions about the robustness of research designs employed to study DMH barriers remain unanswered. This review aimed to identify methodological approaches to identifying barriers to DMH use. Method: Using PRISMA-SCr guided scoping review methodology, the research methods and designs used to study barriers to DMH use among MHPs and consumers were investigated. Four databases were searched using broad terms to identify articles that focused on exploring barriers to DMH use by MHPs and consumers, covering screening, assessment, diagnosis, therapy, counselling, and treatment of mental health issues. Results: One hundred and forty-seven papers met the inclusion criteria. Ninety-six studies were qualitative, 25 were quantitative, and 25 were mixed methods. There were 66 consumer studies, 62 MHP studies, and 19 studies included both. Hundred and eight studies were published between 2017 and 2021, focusing on developed nations such as the USA, Australia, and the United Kingdom. Discussion: There is increasing interest in the barriers to DMH use, with more research employing qualitative designs to identify DMH use barriers. Consensus regarding key terms and definitions; reliable and valid tools to measure DMH use barriers; and increased efforts to test specific DMH tools in more than one setting are needed to enable a better understanding of factors that influence MHPs’ and consumers’ use of DMH.