Childhood obesity is a significant public health issue. This study aimed to evaluate the prevalence of overweight and obesity among 8- and 9-year-old children in Szczecin, Poland, and unlike other studies to assess differences in nutritional status within a single urban agglomeration of nearly 500,000 residents, it was influenced by place of residence and socioeconomic status. The study included 4705 children (2327 boys and 2378 girls) aged 8 and 9 years, attending 50 primary schools in Szczecin (45 public, 5 private) across four districts: North, Right Bank, City Center, and West. Anthropometric measurements were used to calculate BMI. Overweight was diagnosed when BMI was ≥85th percentile but lower than the 95th percentile for age and sex, while obesity was when the BMI was ≥95th percentile. Data on parental BMI, education, and place of residence were also collected. The prevalence of overweight was 16.6%, and obesity was 6.2%. Overweight was more common in girls, while obesity was more frequent in boys. Children attending special education schools and living in the Right-Bank district had the highest rates of overweight and obesity. Parental obesity and low parental education, particularly the father's, were the strongest risk factors for excess body weight. Differences in childhood nutritional status exist even within the same city, influenced by residence and socioeconomic factors. Parental obesity, low education, living in the city's rural districts, and attending special education schools are key risk factors. Enhanced prevention programs tailored to these factors are crucial to combat childhood obesity effectively.