© 2020 American College of Cardiology Foundation Background: When measured in adolescence or young adulthood, cardiovascular health (CVH) is associated with future subclinical cardiovascular disease (CVD), but data are lacking regarding CVD events or mortality. Objectives: This study examined associations of CVH at ages 18 to 30 years with premature CVD and mortality. Methods: This study analyzed data from the CARDIA (Coronary Artery Risk Development in Young Adults Study). CVH was scored at baseline (1985 to 1986) using Life's Simple 7 metrics and categorized as high (12 to 14 points), moderate (8 to 11), or low (0 to 7). CVD events and cause-specific mortality were adjudicated over 32 years of follow-up. Adjusted associations were estimated using Cox models and event rates and population attributable fractions were calculated by CVH category. Results: Among 4,836 participants (mean age: 24.9 years, 54.8% female, 50.5% Black, mean education: 15.2 years), baseline CVH was high (favorable) in 28.8%, moderate in 65.0%, and low in 6.3%. During follow-up, 306 CVD events and 431 deaths occurred. The adjusted hazard ratios for high (vs. low) CVH were 0.14 (95% confidence interval [CI]: 0.09 to 0.22) for CVD and 0.07 (95% CI: 0.03 to 0.19) for CVD mortality, and the population attributable fractions for combined moderate or low (vs. high) CVH were 0.63 (95% CI: 0.47 to 0.74) for CVD and 0.81 (95% CI: 0.55 to 0.92) for CVD mortality. Among individuals with high CVH, event rates were low across sociodemographic subgroups (e.g., CVD rates per 1,000 person-years: age 18 to 24 years, 0.64; age 25 to 30 years, 0.65; men, 1.04; women, 0.36; Blacks, 0.90; Whites, 0.50; up to/through high-school education, 1.00; beyond high-school education, 0.61). Conclusions: High CVH in late adolescence or young adulthood was associated with very low rates of premature CVD and mortality over 32 years, indicating the critical importance of maintaining high CVH.