Background Arterial stiffness predicts the risk of cardiovascular events and all‐cause mortality and is associated with age and hypertension. However, the magnitude of the relationship between blood pressure (BP) and progression of arterial stiffness is unclear, limiting our understanding of how arterial stiffness mediates clinical effects of hypertension and planning of clinical trials. Methods and Results Medline and EMBASE were searched for prospective studies reporting linear models between baseline BP and progression of arterial stiffness, with and without adjustment for demographic characteristics and baseline stiffness. Standardized and unstandardized β coefficients for pulse wave velocity were combined by fixed and random effects meta‐analysis, weighted by the inverse variance. Of 566 fully reviewed articles from 30, 524 titles, 22 populations from 21 reports were included. In 9 cohorts, there were consistent, adjusted associations between baseline systolic BP and progression of arterial stiffness (11 781 patients; standardized β=0.041; 95% CI, 0.026–0.055; P <0.001; P value for heterogeneity=0.70), equivalent to a 1.14‐m/s increase in standard carotid‐femoral pulse wave velocity per decade per 20–mm Hg systolic BP, independent of age. Unstandardized, adjusted associations were similar (1762 patients; β=0.0047; 95% CI, 0.004–0.006; P <0.001; P value for heterogeneity=0.64), equivalent to a 0.94‐m/s increase per decade per 20–mm Hg systolic BP. In limited studies, standardized associations between mean BP and arterial stiffness progression were not significant and heterogeneous (913 patients; β=0.039; 95% CI, −0.008 to 0.086; P =0.11; P value for heterogeneity=0.03). Conclusions Baseline systolic BP was associated with a clinically important progression of arterial stiffness, independent of age, providing a reference for the potential effect of arterial stiffness in mediating changes in clinical outcomes associated with hypertension and providing a reference value to aid clinical trial design.