Objectives: To examine the prevalence of overweight and obesity in school-age children in Isparta Province, Turkiye, during the coronavirus disease 2019 (COVID-19) pandemic, and to compare the results with those of previous studies conducted in Isparta in 2005, 2009, and 2014. Methods: The study was carried out in schools in the city center of Isparta in March 2022, during which the weight and height of students were measured using a scale and stadiometer, and the body mass indices (BMI), BMI percentiles, and z scores were calculated. Results: Of the 8871 students assessed, 4547 (51.3%) were female and the mean age of the sample was 11.92 ± 3.42 (6–18.93) years. The prevalence of overweight was 12%, the prevalence of obesity was 14.5%, and the prevalence of overweight + obesity was 26.5%. A comparison of the figures since 2005 revealed the prevalence of overweight to be stable, while the prevalence of obesity and the prevalence of overweight + obesity were found to have witnessed a increase (χ 2 : 57.01, P < 0.001). The prevalence of obesity was 13% among girls under 11 years of age and 14.3% among girls over 11 years of age; and 18.2% and 12.8% among boys under and over 11 years of age, respectively (χ 2 : 23.26, P < 0.001). The prevalence of obesity was significantly higher in boys under 11 years of age. Conclusions: The prevalence of overweight + obesity was nearly stable in the 3 studies conducted over the 17-year period, but we witnessed an increase in our most recent study conducted during the pandemic. The prevalence of obesity is significantly higher in boys under 11 years of age.