Kenyan studies relating body composition (BC) and blood pressure (BP) have focused on adults. Insight into this relationship among children and adolescents provides evidence for reduction of adulthood cardiovascular disease-risk development. We describe BC and BP correlation among Kenyan children and adolescents. This cross-sectional study randomly sampled 389 school-going participants. Weight, height, BP, waist circumference (WC) and hip circumference were measured. Waist-to-hip ratio (WHR), waist-to-height ratio (WHtR) and body-mass-index (BMI) were calculated. Relationships between BP and WC, WHR, WHtR and BMI were determined. Males and females were 14.7±2.9 and 14.4±2.5 years old, respectively. Secondary and primary schools’ males had SBP 119.1±10.3 mmHg and 107.4±13.7 mmHg; females 111.2±11.8 mmHg and 106.7±11.7 mmHg respectively. The DBP in secondary and primary schools’ males was 69.2±7.8 mmHg and 65.7±8.6mmHg, and, 69.6±7.9 mmHg and 68.1±7.4 mmHg for females. Higher BMI, WC, and WHtR correlated with higher SBP in both sexes (Pearson’s “R” +0.3 to +0.5; p<0.05). In females, DBP correlated with BMI, WC and WHtR, and only with WC for males. In all schools, only WC correlated with SBP in both sexes, BMI, WHR and WHtR correlating only among females. For males, BMI in primary and WHtR and WHR in secondary schools additionally correlated with SBP. For females, BMI and WHtR had correlations across school levels. For private and public schools, BMI, WC and WHtR had +0.2 to +0.6 correlations with SBP. The DBP correlated with WC and WHtR among private schools’ males, and, with WHtR and BMI in both school sets for females. For both sexes, WC had strongest and WHR weakest correlation with SBP. Only in secondary school females did DBP correlate some BC variables. In both sexes, BMI, WC and WHtR all fairly correlated with SBP in private and public schools, WHR appearing least applicable in predicting Kenyan children and adolescents’ BP.