Saudi Arabia is one of the Middle Eastern countries with the highest prevalence of overweight and obesity in adults and especially in females. Overweight and obesity affect many systems in the body leading to increased mortality, morbidity, and risk for many diseases. This study aimed to determine the effects of overweight and obesity on the immune system cells, hematology, lipid profile, and C-reactive protein (CRP) concentration in 62 randomly chosen Saudi female university employees with an age range of 24-52 years. Blood samples were collected from the subjects and they were categorized using the body mass index (BMI), Waist-to-hip ratio (WHR), and waist circumference (WC) as adiposity measures. All results were compared to the controls. The lymphocyte count for the obese BMI group and eosinophil percent for the overweight BMI group were significantly higher. The total leucocyte and neutrophil counts, and triglyceride concentration were significantly higher for the WHR high-risk group. The total leucocyte, neutrophil, red blood cell counts, and concentrations of CRP and triglyceride were significantly higher for the WC high risk; the neutrophil percent was significantly lower for the WC moderate-risk group, and the basophil percent was significantly lower for the WC high-risk group. The remaining parameters and comparisons were not significantly different between the groups of each adiposity measure. In conclusion, overweight and obesity lead to some effects on the immune system and higher inflammation as evidenced by the higher total and some types of leucocytes and CRP concentrations. The effects on hematology and lipids were minimal. Finally, the WC is the best measure of adiposity for the subjects of the study since it resulted in more significant differences between groups compared to the BMI and WHR.