Hypertension induces left atrial (LA) and left ventricular (LV) dysfunction, and an increase in arterial stiffness. This study aimed to investigate the associations of brachial-ankle pulse wave velocity (baPWV) with LA stiffness and LA phasic function in hypertension. A total of 305 hypertensive inpatients enrolled and were divided into two groups based on baPWV [Group I, baPWV ≤ 1515 (cm/s), n = 153; Group II, baPWV > 1515 (cm/s), n = 152]. Two-dimensional speckle tracking echocardiography (2D-STE) based LA phasic strains (LAS-S, LAS-E, LAS-A) and LV global longitudinal strain (LVGLS) were evaluated. LA stiffness index (LASI) was defined as the ratio of E/eʹ to LAS-S. Multivariate linear regression modeling was used to analyze the associations of baPWV with LASI and LA phasic function in all patients as well as age-specific and sex-specific subgroups. LASI was significantly higher in Group II [0.35(0.26, 0.52)] compared with Group I [0.26(0.20, 0.36)] (P < 0.001). After adjusting cardiovascular risk factors, medication, and LV structural and functional parameters (LVEF, LVMI, E/A ratio, and LVGLS), baPWV remained significantly correlated with LASI (P < 0.05). We also evaluated the predictive value of baPWV for LASI, the area under the curve (AUC) was 0.663 (95% CI: 0.607–0.716, P < 0.001). In conclusion, BaPWV was independently associated with LA stiffness in hypertensive inpatients. BaPWV also exhibited a certain predictive value for LA stiffness in these inpatients. Measuring arterial stiffness can provide clinicians clues for early cardiac target organ damage (TOD) in addition to vascular TOD.