Extensive evidence shows that risk factors for cardiovascular disease (CVD) begin to develop early in life. Childhood obesity and elevated blood pressure (BP) have become overwhelmingly challenging, with 57% of today's children predicted to be obese by the age of 35 years, and global rates of hypertension in children and adolescents increasing by 75% from 2000 to 2015. Thus, there is an urgent need for tools that can assess early CVD risk in youth, which may lead to better risk stratification, preventative intervention, and personalised medicine. Vascular ageing (the deterioration in vascular structure and function) is a pivotal progenitor of health degeneration associated with elevated BP. Exposure to adverse environmental and genetic factors from fetal life promotes the development and accumulation of subclinical vascular changes that direct an individual towards a trajectory of early vascular ageing (EVA)—an independent predictor of target organ damage in the heart, brain, and kidneys. Therefore, characterising vascular ageing from youth may provide a window into cardiovascular risk later in life. However, vascular ageing measurements only have value when techniques are accurate/validated and when reliable thresholds are available for defining normal ranges and ranges that signal increased risk of disease. The aim of this paper is to summarise current evidence on the importance of vascular ageing assessment in youth and the impact of interventions to prevent or delay EVA, to highlight the need for standardisation and validation of measurement techniques in children and adolescents, and the importance of establishing reference values for vascular ageing measures in this population.