Introduction People living with asthma require regular reviews to address their concerns and questions, assess control, review medication, and support self-management. However, practical barriers to attending face-to-face consultations might limit routine reviews. Reviewing asthma using asynchronous digital health interventions could be convenient for patients and an efficient way of maintaining communication between patients and healthcare professionals and improving health outcomes. We, therefore, aim to conduct a mixed-methods systematic review to assess the effectiveness of reviewing asthma by asynchronous digital health interventions and explore the views of patients and healthcare professionals about the role of such interventions in delivering asthma care. Methods We will search MEDLINE, Embase, Scopus, PsycInfo, CINAHL, and Cochrane Library from 2001 to present without imposing any language restrictions. We are interested in studies of asynchronous digital health interventions used either as a single intervention or contributing to mixed modes of review. Two review authors will independently screen titles and abstracts, and retrieve potentially relevant studies for full assessment against the eligibility criteria and extract data. Disagreements will be resolved by discussion with the review team. We will use ‘Downs and Black’ checklist, ‘Critical Appraisal Skills Programme’, and ‘Mixed Methods Appraisal Tool’ to assess methodological quality of quantitative, qualitative, and mixed-methods studies respectively. After synthesising quantitative (narrative synthesis) and qualitative (thematic synthesis) data separately, we will integrate them following methods outlined in the Cochrane Handbook for Systematic Reviews of Interventions. Conclusion The findings of this review will provide insights into the role of asynchronous digital health interventions in the routine care of people living with asthma. Trial registration Systematic review registration: PROSPERO registration number: CRD42022344224.