Health disparities among historically disadvantaged populations can undermine the effectiveness of eHealth and mHealth interventions and limit their acceptability among diverse community members. The twin aims of this umbrella review of systematic reviews (SRs) are to summarise the evidence on the characteristics and effectiveness of eHealth and mHealth interventions among underserved populations in developed counties and provide recommendations to community organizers, policy makers and researchers. Comprehensive searches were conducted in bibliographic databases, Google Scholar and references lists for SRs published in English between 2000 and 2019. SRs were selected following a protocol registered with PROSPERO. Two independent reviewers were involved in the selection appraisal process, quality assessment and data extraction process. Six SRs met the inclusion criteria for this umbrella review. The six SRs concerned interventions delivered by computer programmes, cell-phones or other electronic devices. The studies in the SRs reported improvements to physiological wellbeing, health knowledge and self-management, as well as improvements in psychosocial outcomes. This umbrella review concludes with recommendations for community organizers, policy makers and researches for the formation of guidelines, inclusion of target community members in the development of eHealth interventions and directions for future research.