The literature on childhood-onset depression and future compromised vascular function is suggestive but limited. The objective of this study was to determine if arterial stiffness, a predictor of future cardiovascular disease (CVD), measured in young adulthood, is associated with childhood-onset depression. Cardiometabolic risk factors and pulse wave velocity (PWV), a measure of arterial stiffness, were cross-sectionally assessed in young adults with a history of childhood-onset depression (clinical diagnosis of major depressive episode or dysthymic disorder; N = 294 probands; initially recruited via child mental health facilities across Hungary; mean age of first depressive episode = 10.4 years), their never-depressed full biological siblings (N = 269), and never-depressed controls (N = 169). The mean ages of probands, siblings, and controls at the PWV visit were 25.6, 25.0, and 21.7 years, respectively, and 8.8% of the probands were in a current depressive episode. Controlling for age, sex, age*sex, education, and family clusters, PWV (m/s) did not statistically differ across the groups (probands = 7.01; siblings = 6.98; controls = 6.81). However, after adjusting for key covariates, there were several across-group differences in CVD risk factors: compared to controls, probands and siblings had higher diastolic blood pressure and lower high-density lipoprotein cholesterol, probands had higher triglycerides, and siblings had higher body mass index (all p < 0.05). We found limited evidence of an association between a history of childhood-onset depression and young adulthood arterial stiffness. However, our findings of elevated cardiovascular risk factors in those with childhood-onset depression suggest that pediatric depression may predispose to increased CVD risk later in life and warrants further investigation. •Pediatric depression was not associated with young adulthood arterial stiffness.•Pediatric depression was associated with adverse young adulthood CVD risk factors.•These risk factors include diastolic blood pressure, HDL-c and triglycerides.•Childhood-onset depression may predispose youth to CVD risk later in life.