Sedentary behaviour is associated with a greater predisposition to developing cardiovascular diseases. The aim of the study was to analyse the relationship between sedentary time and early vascular ageing. A total of 501 participants (49.70% men) were recruited through random sampling stratified by age group and sex. Vascular ageing was evaluated considering three criteria: (1) the vascular ageing index (VAI); (2) the carotid–femoral pulse wave velocity (cfPWV) 10th and 90th percentiles of the reference values in the European population by age; and (3) the Framingham’s heart age. The carotid intima–media thickness was measured using a Sonosite Micromaxx ultrasound, the presence of peripheral artery disease was assessed by calculating the ankle–brachial index using a VaSera VS-1500, and the cfPWV was measured with a SphygmoCor® device. Weekly sedentary hours were evaluated through a sitting time questionnaire. The average age of the population was 55.90 ± 14.24 years. The men spent more hours sitting per week (47.6 ± 16.6 vs. 36.8 ± 17.3 h/W), at work (16.7 ± 16.2 vs. 9.73 ± 14.9 h/W), and watching TV (21.6 ± 12.5 vs. 18.7 ± 11.9 h/W). In the logistic regression analysis, the individuals with early vascular aging (EVA), with respect to those with healthy vascular aging (HVA), spent more hours sitting per week (OR = 1.03 vs. OR = 1.02; p < 0.05) and watching TV (OR = 1.03 vs. OR = 1.03; p < 0.05), using the criteria of the European guideline and VAI, and more hours sitting when commuting (OR = 1.04; p < 0.05), using Framingham’s heart age to define EVA. The results of this study indicate that sedentary time is associated with early vascular ageing. Therefore, reducing sedentary time would improve vascular health.