Objective: There is a tremendous opportunity for electronic health services (eHealth) to reach adults with low income who want to participate in weight loss interventions, but face barriers in access. This review (a) synthesizes and presents results from all studies evaluating the effectiveness of eHealth weight loss interventions for adults with low income and (b) describes the strategies used to tailor them to these groups. Method: Electronic databases were searched for studies examining the effectiveness of eHealth weight loss interventions designed for adults with low income and screened for eligibility by two independent reviewers. All experimental study designs were included. Data were extracted, results were qualitatively synthesized, and studies were assessed for quality. Results: Nine studies met the inclusion criteria (N = 1,606 total participants). Four studies reported significant reductions in weight of small to moderate magnitude among participants in eHealth interventions (M weight loss = −2.2 kg; SD = 1.6). Many studies did not describe how they tailored the intervention for adults with low income; however, studies that achieved significant results tended to use more tailoring strategies. Most studies reported high retention rates. Three studies were rated as strong quality, four as moderate, and two as weak. Conclusions: Evidence is limited that eHealth weight loss interventions for this population are effective in achieving clinically and statistically significant weight reductions. While interventions that used more tailoring strategies tended to be more effective, studies that use the rigorous methodology and describe interventions in more depth could better elucidate whether eHealth interventions are an effective approach in this population.