OBJECTIVE. Childhood overweight and obesity may result in premature onset of cardiovascular risk factors such as hypertension. Rural populations in North America may be at increased risk for overweight. We evaluated whether overweight and obesity were associated with prehypertension and hypertension in a well-characterized population of children in rural Canada. METHODS. The study population for this cross-sectional study was composed of children (aged 4–17 years) who were participants of the Walkerton Health Study (Canada) in 2004. Prehypertension and hypertension were defined on the basis of percentiles from the average of 3 blood pressure measures taken on a single occasion. Percentiles for BMI and blood pressure were calculated by using the 2000 Centers for Disease Control and Prevention growth charts. Multinomial logistic regression was used to evaluate the odds for prehypertension and hypertension resulting from overweight and obesity. RESULTS. Of 675 children (98.7% white), 122 (18.1%) were overweight and 77 (11.4%) were obese. Prehypertension and hypertension were detected in 51 (7.6%) and 50 (7.4%), respectively. After adjustment for family history of hypertension and kidney disease, obesity was associated with both prehypertension and hypertension. Overweight was associated with hypertension but not prehypertension. These associations were observed across the genders and children aged <13 and ≥13 years, except that overweight was not associated with hypertension among girls. CONCLUSIONS. In this population of children who lived in a rural community in Canada, overweight and obesity were strongly associated with elevated blood pressure. Whether blood pressure normalizes with improvements in diet, physical activity, and environment is an area for additional study.