Background: Type 2 Diabetes Mellitus (T2DM) poses a significant health and financial burden to individuals and healthcare systems. Omega-3 polyunsaturated fatty acids (PUFA) possess numerous properties (e.g. anti-inflammatory, anti-thrombotic, anti-lipidemic) that may be beneficial in the management of T2DM and its complications. Methods: In this narrative review, we discuss the potential mechanisms, clinical evidence-base, and practical considerations regarding the use of omega-3 PUFA supplementation for the management of glycaemic control and common comorbid conditions, including diabetic nephropathy and retinopathy, liver disease, cognition and mental health, and cardiometabolic disease. Results/conclusion: Omega-3 PUFA supplementation is generally well-tolerated and does not appear to be contraindicated for patients on anticoagulant therapy; however, uncertainty persists regarding the purity and stability of commercial omega-3 PUFA products. Despite promising animal studies, the current clinical evidence for the use of omega-3 supplementation for the management of T2DM and associated conditions is both limited and conflicting. Results from existing clinical trials do not support the use of omega-3 PUFA for glycaemic control and there are limited studies in T2DM populations to support the use of omega-3 PUFAs for associated complications of diabetes. Possible contributors to the conflicting evidence base are study design issues, such as inadequate intervention period, sample size, omega 3 supplement dose, variations in the EPA to DHA ratio and clinical heterogeneity among diabetic populations.