Video telehealth can offer people convenient, real-time access to clinicians without arranging transportation or time off work. Among people with diabetes, this study examines the association between video telehealth access and changes in HbA1c. This longitudinal cohort study (2016-2019) used linear regression with person-level fixed effects, stratified by baseline HbA1c (last value in 2015), to examine the association between video visit access and changes in HbA1c. HbA1c values were categorized into 3 periods of video visit exposure: (1) before any video visit, (2) during video visit transition year (calendar year of the first video visit), and (3) after video visits. The model compared changes in HbA1c values collected before the patient had any video visits with those collected after the transition year. Analyses were conducted in September 2020. Among 204,301 people with diabetes, video visit access was associated with a statistically significant reduction of 0.15 (95% CI= -0.19, -0.11) percentage points in HbA1c, with greater reductions among patients with an elevated baseline HbA1c value (-0.22 percentage points, 95% CI= -0.32, -0.11) and with no baseline HbA1c measurement (-0.39 percentage points, 95% CI= -0.71, -0.07). Gaining access to video telehealth was associated with reductions in HbA1c among people with diabetes. Video telehealth offers people with chronic conditions a new, convenient way to access health care, is not associated with worsening HbA1c, and may support better disease management, particularly among patients with higher baseline HbA1c.