CONTEXT: Over the past 2 decades, overweight and obesity rates have increased exponentially, along with related comorbidities including type 2 diabetes, hypertension, cardiovascular disease, and some cancers. The Mediterranean Diet (MDiet) has been suggested as a potential way to mitigate the health burdens related to overweight and obesity. OBJECTIVE: For this review, the literature on MDiet-focused digital interventions was examined to determine efficacy, best practices, and potential limitations. DATA SOURCES: The search was conducted across 15 databases for relevant publications published through April 2020 in English, French, Spanish, Arabic, or Italian. DATA EXTRACTION: Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed using a combination of keywords and phrases and evaluated independently for relevance, merit, and inclusion and exclusion criteria. DATA ANALYSIS: The systematic literature review resulted in 15 articles that met the search criteria. Ten interventions were delivered online, and 5 were delivered via smartphone using an app. The majority of online MDiet-focused interventions were effective, particularly when modeled after evidence-based and best-practice online nutrition education interventions. Such interventions also are effective for promoting positive health behaviors and health outcomes, such as increased physical activity, increased levels of high-density lipoprotein cholesterol, and a lower total high-density lipoprotein cholesterol ratio. CONCLUSION: Technology-based interventions to educate and promote adherence to the MDiet are successful in helping individuals achieve the stated outcomes. More research is needed to determine the efficacy of MDiet interventions delivered via smartphone apps.