Abstract: Previous research on the effect of replacing sources of animal protein with plant protein on glycemic control has been inconsistent. We therefore conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to assess the effect of this replacement on glycemic control in individuals with diabetes. We searched MEDLINE, EMBASE, and Cochrane databases through 26 August 2015. We included RCTs ¥ 3-weeks comparing the effect of replacing animal with plant protein on HbA, fasting glucose (FG), and fasting insulin (FI). Two independent reviewers extracted relevant data, assessed study quality and risk of bias. Data were pooled by the generic inverse variance method and expressed as mean differences (MD) with 95% conﬁdence intervals (CIs). Heterogeneity was assessed (Cochran Q-statistic) and quantiﬁed (I 1c-statistic). Thirteen RCTs (n = 280) met the eligibility criteria. Diets emphasizing a replacement of animal with plant protein at a median level of ~35% of total protein per day signiﬁcantly lowered HbA (MD = 0.15%; 95%-CI: 0.26, 0.05%), FG (MD = 0.53 mmol/L; 95%-CI: 0.92, 0.13 mmol/L) and FI (MD = 10.09 pmol/L; 95%-CI: 17.31, 2.86 pmol/L) compared with control arms. Overall, the results indicate that replacing sources of animal with plant protein leads to modest improvements in glycemic control in individuals with diabetes. Owing to uncertainties in our analyses there is a need for larger, longer, higher quality trials. Trial Registration: ClinicalTrials.gov registration number: NCT02037321.