Background: Hypertension is a major global public health concern and a leading contributor to cardiovascular morbidity and mortality. Despite pharmacological treatment, blood pressure (BP) control remains inadequate in many patients, highlighting the need for complementary, non-pharmacological approaches. Objective: The aim of the study was to evaluate the effect of olive leaf infusion consumption on systolic (SBP) and diastolic (DBP) in hypertensive adults and to explore associated cardiometabolic and lifestyle factors. Material and Methods: A preliminary dietary survey was conducted to assess the daily salt intake of hypertensive patients recruited at the Mohammed Boudiaf Public Hospital Relizane, Algeria. Only patients with a comparable daily salt intake (6 to 8 g/day) (220 patients) were selected to participate in a six-week prospective observational study, after being divided into two groups: a control group A (n = 110) and an experimental group B (n = 110) consuming an olive leaf infusion twice a day at fixed times before meals (once in the morning and once in the evening), in addition to the same diet. BP was measured weekly. Anthropometric, clinical, and lifestyle data were collected through structured interviews. Temporal changes in BP were analyzed using repeated-measures ANOVA with Greenhouse-Geisser correction, and correlation analyses were performed to assess associations between variables. Baseline characteristics, including age and hypertension severity, were comparable between groups. Results: Olive leaf infusion consumption was associated with a significant reduction in SBP and DBP from the second week onward. Repeated measures ANOVA demonstrated a significant main effect of time on SBP (p < 0.001) and a significant time and group interaction (p < 0.001). DBP showed similar effects (time and group interaction, p < 0.001), with BP reductions plateauing after week four. Correlation analyses identified significant associations between BP, salt intake, obesity indices, and sleep disturbances. Short-term consumption of olive leaf infusion was associated with clinically meaningful reductions in SBP and DBP in hypertensive adults. Conclusions: These findings support olive leaf infusion as a potential complementary, non-pharmacological strategy within integrated hypertension management. Standardized phytochemical characterization is needed to confirm efficacy and guide clinical implementation.