Objective: This purpose of this study was to conduct a rapid review and environmental scan of diabetes online communities (DOCs) to highlight the clinical impact of DOC engagement and provide guidance to health care providers for navigating and prescribing DOCs. Methods: This two-phase review included a rapid review of clinical outcomes and an assessment of DOC content. We conducted a literature search for studies evaluating DOC use and glucometric (glycated hemoglobin [A1C], time-in-range, hypoglycemia), behavioral, and psychosocial outcomes. The environmental scan of current DOC sites established key features, including available platforms, target population, content areas, and reach. Results: Twelve papers were included—eight reported DOC use within a context of do-it-yourself (DIY) noncommercial, opensource hybrid closed loop systems community and four were non-DYI related. In latter, all studies were cross-sectional, describing patient-reported outcomes. Two studies reported A1C lowering with DOC use, two DOC use was associated with high self-efficacy, one showed association with higher self-care levels, and one showed higher quality of life scores when compared with population norms. All DIY studies showed improvement in glucometrics after initiation of sensor augmented pump technology with DOC support. Of 54 DOC sites reviewed in the environmental scan, 29 were included. Diabetes online community sites were heterogenous in social media platform and type of diabetes targeted. Conclusion: Diabetes online communities have the potential to improve clinical, behavioral, and psychosocial outcomes. Randomized control trials and/or longitudinal prospective studies evaluating outcomes are needed to further examine the potential benefits of DOC use. Diabetes online communities are diverse and span a variety of social media platforms, providing clinicians opportunities to individualize recommendations for DOC use.