Hypertension has been established as a common health condition in young people. Most studies have focused on the impact of body mass index (BMI), but the relationships between body composition parameters and blood pressure in Palestinian children has not previously been investigated. We aimed to analyze the prevalence of overweight/obesity and elevated blood pressure/hypertension and investigate the associations among obesity-related parameters, including anthropometric and body composition markers and blood pressure levels in a population of 971 Palestinian school children (50% girls; mean age 10.3 ± 1.1 years). Anthropometric measurements including height, waist circumference (WC), hip circumference (HC), waist-to-hip ratio (WHR), and waist to height ratio (WHtR) were assessed. A body composition analyzer was used to measure body weight, fat mass, and fat-free mass. Blood pressure including systolic (SBP), diastolic (DBP) and mean arterial pressure (MAP) were measured using a Dinamap vital signs monitor. The prevalence of overweight/obesity was 25.3% in the girls and 23.1% in the boys. 26.3% of the children had elevated systolic blood pressure, or systolic hypertension; whereas 23.4% had elevated diastolic blood pressure, or diastolic hypertension. All obesity-related variables, with the exception of WHR and WHtR, showed statistical differences among the normotension, elevated blood pressure and hypertension groups for systolic and diastolic blood pressure (p < 0.05). Children with elevated blood pressure or hypertension had significantly higher weight, BMI, WC, HC, fat mass, and fat-free mass values compared to participants with normotension, supporting the direct association between obesity and hypertension in this population. Weight-reduction interventions are essential for reducing the prevalence of childhood hypertension in Palestinian children.