Background Ensuring high quality care for persons with diabetes remains a challenge for healthcare systems globally with consistent evidence of suboptimal care and outcomes. There is increasing interest in quality improvement strategies to improve diabetes management as reflected by a growing number of systematic reviews. These reviews are of varying quality and dispersed across many sources. In this paper, we present an overview of systematic reviews evaluating the impact of interventions to improve the quality of diabetes care. Methods We searched for systematic reviews evaluating the effectiveness of any intervention intended to improve intermediate patient outcomes and process of care measures for patients with any type of diabetes. Two reviewers independently screened search results, appraised each systematic review using AMSTAR and extracted data from high quality reviews (AMSTAR score ≥ 5). Within reviews, we used vote counting by direction of effect to report the number of studies favouring an intervention for each outcome. We produced summaries of results for each intervention category. Results We identified 125 reviews of varying methodological quality and summarised key findings from 50 high quality reviews. We categorised reviews by quality improvement intervention. Eight reviews were broad based (involving a variety of strategies). Other reviews considered: patient education and support (n = 21), telemedicine (n = 10), provider role changes (n = 7), and organisational changes (n = 4). Reviews reported intermediate patient outcomes (e.g. glycaemic control) (n = 49) and process of care outcomes (n = 9). There was evidence of considerable overlap of included studies between reviews. Conclusions There is consistent evidence from high quality systematic reviews that patient education and support, provider role changes, and telemedicine are associated with improvements in glycaemic and vascular risk factor control in patients. There is less evidence about the impact of quality improvement interventions on other key process measures such as screening patients for diabetic complications. This paper provides decision makers with a comprehensive overview of evidence from high quality systematic reviews about the effects of quality improvement interventions on improving diabetes care.