Prior studies have established the correlation between oxidative balance score (OBS) and hypertension (HTN). While the association between OBS and resistant hypertension (RHT) as well as arterial stiffness among individuals with hypertension remains undisclosed. In this study, total of 15,910 adults diagnosed with hypertension were enrolled from NHANES 2001–2018. OBS was calculated and categorized into quartiles. Weighted regression model, stratified analyses and restricted cubic spine (RCS) were employed to evaluate the association between OBS and RHT, major adverse cardiovascular events (MACEs) and arterial stiffness in individuals with hypertension. Among enrolled participants, high OBS quartiles consistently demonstrated a negative association with resistant hypertension across all models (all p < 0.05), indicating robust stability. Compared with the lowest OBS quartile, the risk of resistant hypertension in the highest OBS quartile was decreased by 30.8% (95%CI 0.471–0.995, p = 0.049). After dividing OBS into dietary OBS and lifestyle OBS, a significant inverse association with lifestyle OBS and RHT was observed. With regard to MACEs, the inverse association was also found in participants with high OBS. Besides, the potential relation between OBS and arterial stiffness was explored and we found OBS was significantly associated with decreased arterial stiffness (β for ePWV, −0.014; 95%CI -0.026 to −0.001; p = 0.032). RCS analysis confirmed a nonlinear association between OBS and RHT, MACEs, cardiovascular death and nonfatal MI among participants with hypertension. Elevated OBS was negatively associated with the risk of RHT and arterial stiffness among US adults with hypertension. •Elevated Oxidative Balance Score (OBS) was significantly inversely associated with resistant hypertension, as well as arterial stiffness.•OBS is negatively associated with the risk of major adverse cardiovascular events (MACEs) among US adults with hypertension.•Adopting a healthy diet and lifestyle rich in antioxidants to increase the OBS may aid in blood pressure control and slow the progression from hypertension to adverse cardiovascular events.