A total of 14,660 individuals were included in the study. A fasting blood sample and 2-hour post-glucose load blood sample from each participant were analysed for blood sugar. Participants were classified as diabetic or non-diabetic and as either obese (BMI > 30 kg/m2), overweight (BMI 25-29.9 kg/m2) or normal (BMI < 25 kg/m2). The prevalence of obesity was calculated in the total sample and separately for diabetic and non-diabetic males and females. The results showed obesity and overweight in 13.05% and 27.23% of males and 20.26% and 25.20% of females respectively. The prevalence of both obesity and overweight were significantly higher among diabetics than non-diabetics. In each province, diabetics had a significantly higher prevalence of obesity than non-diabetics. Several interprovincial variations were seen. Public education on obesity and overweight and ways to decrease them are recommended in Saudi Arabia.