Hypertension can originate in childhood and remain undetected unless special screening is performed. The burden of hypertension in adolescents in Tunisia is unknown. The aim of this study was to investigate the prevalence of blood pressure (BP) within the hypertension range and its association with other risk factors among Tunisian adolescents. A cross-sectional study that included 1385 secondary school students in Sousse, Tunisia, was performed during 2017–2018. A two-stage cluster sampling strategy was used to obtain a representative sample of the study population. BP within the hypertension range (HBP)was classified following the European guideline recommendations for measuring BP in children and adolescents. Anthropometric indices were measured using a standard protocol. A structured questionnaire collected information about sociodemographic characteristics, lifestyle, mental health status, and addictions. Adjusted logistic regression models were used to assess hypertension-related risk factors. Our study included 39.5% boys and 60.5% girls. The mean age of our population was 17 ± 1.5 years. The prevalence of HBP was 15.4% (13.1–18.0%), and it was significantly higher in boys (22.8%) than in girls (10.6%, p value < 0.001). In the multivariate logistic regression model, overweight [OR = 1.72(1.18–2.51)] and obesity [OR = 3.73(2.55–5.41)] were independent risk factors for HBPrange, (p value < 0.001), whereas female sex [OR = 0.41(0.29–0.56), p value < 0.001] and depression [OR = 0.67(0.51–0.88), p value = 0.008] were independent protective factors. Among Tunisian secondary school adolescents, the prevalence of HBP was high and associated with excess body weight. A comprehensive strategy for the prevention of hypertension and its risk factors among youth is urgently needed.